gut feeling. and then talk about life-style/cleaning habits/money. Best solution for cleaning (because two people will always have different opinions): have a plan. as in: written in a calendar who cleans what when.
I've been extremely lucky with roommates, I had one bad roommate so far. )

Not insane.
Had the room mate who "borrowed" my jewelry from my room to wear to her house cleaning jobs. The room mate with the cocaine addicted boyfriend who she had secretly living in her room. The woman who kept taking my food out of the fridge to make room for hers, but left my food out all over the counter to spoil. The woman who attacked me in front of the police because I told them to press charges against her teenage son who stole my car in the middle of the night & drove it into a ditch after a 5 mile high speed chase with the police. The woman who thought it would be "fun & kinky" to have sex with her boyfriend in my bed. While I was in it sleeping. The one who thought I would be the live-in babysitter for her weekend visiting daughter. The one who went overseas to visit a guy she met on-line. It was a bit unnerving to have the FBI show up at my job to ask me what I knew about the guy was she was visiting. The FBI. At my job. The one who got rip roaring drunk every night on cases of "near beer"- because she was trying not to drink anymore. Oh, I got stories.
Criteria? NOT insane.

Wow, ecuadoriana1, either you have the worst luck in the world or you need to get some better filters when you choose housemates! Those are crazy stories.
I've lived with 5 different housemates and the only bad experience was someone who was really neurotic about anything being out of place. My experience is also that if 2 people live together, each of them will truly believe that she does the majority of the cleaning and the other does nothing. One person will be fanatical about swiftering the floors but never notice mold in the bathroom, the other will never look at the floors, but obsessively scrub the bathtub. A housekeeper once or twice a month is a sound investment for domestic harmony.
That being said, I sure hope I am done with housemates forever! It helps so much if you love the person you live with.

The only person i've liked living with after moving out from my parents is my boyfriend. We've had 3 roommates living with us for in the past 2 years and i've only liked one of them! We are currently living with one who i just can't stand but i guess that's more me than him but he just really annoys me. I think it would be best for me to live by my self if not with my boyfriend. Being a perfectionist and a tad bit OCD is not fun to live with unless you really love me.
Also a good tip is not to live with your friends, you get sick of them straight away!

I rather live with parents or have a tiniest studio than have a roommate.

There's a special place in hell for the woman who would use my cast iron pans, and then leave them soaking so I would come home to a sink full of rusty water.

@MonicaK, agreed. I haven't had a roommate in 7 years...and I live in a 200 square foot attic studio, haha. Living solo is definitey a "luxury" I'm willing to indulge in.

It's important to have a conversation about your thresholds for things such as cleanliness, clutter, etc. Some people just plain don't notice things like crumbs, dust, toothpaste in the sink, or piles of belongings. While others are sensitive about these areas.

I would have a talk beforehand about what your take is on sharing: food, toiletries, bills.

I had a roommate in college who barely ever bought toilet paper and when she did would buy a measly 4-pack. It made me want to hoard my 24 pack to myself.

If you set out a clear plan from the beginning (ex. "we will share condiments but nothing else in the kitchen"), things shoudl work more harmoniously.

My boyfriend and I recently moved in together after both living alone for 5-plus years each. It's been an adjustment, and yes, it is easier when you love the other person, but I am oh so glad that we had the talk about expectations before the move-in. This included a list of who-does-what. We've evolved a bit from the list, but it gave us a reasonable baseline. Most needed for us were understanding and flesibility since we are both over 40 and quite set in our ways.

@inchbranch When I got a roommate, I specifically talked to him about the proper care of my cast iron pans and my high-carbon steel vegetable knife. He had never used cast iron before. Then, when I got a new wok, my roommate ended up seasoning it for me.

I found that having an every other week cleaning service kept the peace a lot. Because, yes, you will both probably be cleaning, but not realizing what the other is cleaning. One of my old roommates didn't realize how much I cleaned the kitchen until I moved out and she realized that the countertops and floors collected grime very quickly. I was cleaning it at least twice a week if not longer.

For food, have the yours, mine, and ours system. I usually shared staples with roommates and then if something was out we'd alternate restocking.

As far as finding roommates, I have found mine through the internet. One roommate vetted me over the phone because I wasn't moving to the state for a month or so. The next roommate I had was also the vetter. But we got along really well at the interview and then realized, while touring the space, that all of her movies were either movies that I owned, liked, or wanted to see. We got along really well and I moved out when her now-husband moved in and we're still really good friends.

My next roommate was when I was in charge. We set expectation of boundaries and rent splitting and I sprung for the cleaners since I know I tend to get really busy and vacuuming triggers my allergies, so I have someone else do it! We made sure to set ground rules of informing the other when we have people over, or want to have a group over. We lived together for about 2 years very well. We were never best buddies, but we worked well living together.

Ecuadoriana1, you win. I thought I had it bad! My current roommate I met on CL, and she wanted to move in the next day. It was now or never, so I took a risk and said okay. She was awesome for the first four months, then did something really low and disgusting & I called her out on it. I did so much for this girl & thought she was my friend, meanwhile the whole time she's scrutinizing me and my ways in her mind. Insane. Since then she has been trying to justify her wrong doing by literally bullying me. Right now i'm being threatened to court because I wont return her security deposit because she wants to leave early. During an argument I told her I'd give it back if she just got the hell out of my house. Now she is holding me to what I said... Oour lease states that no verbal agreements are valid unless they're in writing and entered into our lease. So, I hope she takes me to court. She truly believes because a verbal statement stands in court, she will win.
So, thanks to this crazy mofo I wont have any more roommates. I want my home to myself! Unless, of course, a friend needs a place to stay for some time. A friend, a good old friend. No more strangers.

The most important question I've found is to ask how they spend their evenings. I work 9-6:30 and often have plans 3-4 nights a week. I definitely did not want a roommate who came straight home after work every day to hang out in our shared space the whole time. I think I'd end up feeling like I was intruding on his/her space--plus, I'd never get the living room to myself.

My experience has been that the best roommates are the ones you like and could easily hang out with for a night, but are not really good friends, and each of you do your own thing. I only had one roommate who became a really good friend, which we both thought was sort of a fluke. Living with friends can sometimes take the joy out of the friendship.
Also, similar philosophies about sleep and quiet - is it okay to do things at a regular volume early in the morning or late at night? Seems like a no brainer to me but I've experienced differently. What's considered early, what's considered late? Define it.

I didn't take seriously my last roommate's previous roommate stories. She told me she lived with her boyfriend, but the break up was messy, she left their shared lease apartment early, and after she left he didn't take care of the place and she was somehow saddled with $1,000+ of cleaning and repair costs by the landlord after the lease was up. I never met the guy, so I assumed he was as described. After living with her for two years I realized she broke stuff all the time and didn't take care of things and that she was likely also responsible for the costs of damage in her last place. Oh, well.

ecuadoriana1... that sounds awful... but I kinda have to wonder about your litmus for choosing roommates, you know? All of mine have been pretty awful, but not *that* awful.

I think it's important to not consider one's self the "ok" part of the equation, and everyone else as either also ok, or not ok in comparison. From their side of things, I was probably too clean (I vacuumed once a week, they never vacuumed, not once -- and yes, that has a touch of the "I'm ok, you're not ok" in it, doesn't it? Her excuse was allergies to carpet). Even spouses have disagreements about all this stuff, so I don't think it matter so much how well you get along or are alike in your habits.

I think the trick is a list of "rules to live by" that you both can agree to, whether you're innately tidy or not, noisy or not, etc. I am not in the habit of washing the kitchen sink out after doing the dishes, but if it was important to someone (my husband) and I agreed to do as part of a living agreement (or to keep the peace), then ok, I'll do it.

Or agree to pay for services that take care of the issue, e.g., there services for everything from walking the dog and scooping dog poop, to house cleaning and gardening, window washing, snow shoveling, grocery delivery, nannies, you name it.

It is worth the extra costs to live alone. I have had roommates from hell, and will never, ever have any again.

I also had a roommate lose my cat off the balcony (only 2nd floor - cat wasn't hurt just never came back.) I also had a roommate who had been stealing from me and my friends for months until we caught on. Credit card fraud, the works! Otherwise, had many FABULOUS roomies who are my friends to this day. Now I just have to put up with my permanent roommate - my husband. :-)

roommate(s)? nevah! I'd rather die than to live with another person. it's me mostly. i can't subject a fellow human to put up with me. so there, no roommate and no live-in boy friend/husband.

distance creates beauty. sadly, many are not in a position to live alone, mostly for financial reason. to them i really don't know what to say other than to wish them the best of luck.

So glad I am done with roommates! It's fine In your twenties, but once people get in their mid 30s and 40s they are so set in their ways, it makes being in roommate situations impossible.

I think I'd rather live in a cardboard box than have roommates. (My current domestic partner is an exception.)

I'm sorry but you are doing it wrong. How the hell do you pick those people? there are always signs. Always! My "worst" roommate was too immature (she yelled at me for taking a shower after she had cleaned the bathroom) With so many bad roommates, you *might* just not be the person who should have roommates.

After reading these stories I am so glad that I was so shy that there was NO WAY ever that I could have had a roommate. I grew up in an area of reasonably priced rental housing, so that helped make it possible.

I think I am one of the few people who really enjoys having a roommate, and cringes at the idea of living alone. I have only had one bad roommate- we were in college and my other roommate and I desperately needed a third person for our new apartment, and she had what I called "puddle-lake" syndrome. If you were worried about one paper she was worried about three, if you had to work a double at work she "had" to work a 20 hour day, etc. It got to the point where I just ignored her, and she seemed to stick to her other, equally dramatic friends. Other than her I love having roommates, being in grad school now I feel like I study/intern so much that if I didn't live with someone I could go days without speaking to people!

In San Francisco, it's hard to afford an apartment without a roommate. I live in a 2 bedroom with my boyfriend and a roommate, and it's currently the only way we could afford this adorable apartment. Once I graduate, I hope to get a job that pays well enough to cover our roommate's share, but for now this will do.

We definitely went on gut feeling when choosing a roommate, eventually ending up with two choices. The guy we picked seemed great — well travelled, big foodie, minimal belongings, very nice. He is still a great guy, but after living together for almost a year I've realized that we would have been better off with the other guy. While I don't have major complaints, there are a few lessons I've learned:

Introvert/extrovert compatibility: I've lived with roommates before, and we've always been pretty reserved, generally staying out of each others way, and avoiding conversation unless we were both in "hang out mode". I guess you could call me an introvert. Our current roommate is the most social dude I've ever met. He ALWAYS wants to small talk, hear about your day, your weekend, your lunch, your trip to the store. He will always sit down next to you in whatever (common) room you're hanging out in. He loves company, while I hate the constant social pressure at home. HELP!

Decoration style: I should have known that designers and engineers don't mix. Again, he's a nice dude, but man, terrible taste in wall art and general decoration. I can't wait until he moves out so I no longer have to stare at the rainbow-colored Einstein print in the living room, and the awful maroon and green towels in the bathroom. And who thought getting a white bathmat was a good idea?

I look forward to living on my own, that's for sure. But I never could have afforded this perfect little apartment without one, and so I'm grateful for that.

I always seem to get stuck with roommates with no jobs that sit around the house all day on the computer.

Perceived emotional stability.

Gainfully employed
Communicative. Not necessarily chatty, but isn't afraid of discussing the occasional issue. This doesn't necessarily need to be verbal. I once lived with a guy who would greet me at the door with a hail of Nerf bullets if there was something we needed to discuss. Gets the message across and is wayyy less confrontational and funnier than "We need to talk."
Clear rules on SOs, cleanliness, pets, and guests.
Clear rules on the kitchen, such as "please do not use an electric hand mixer in my nonstick pans."
Lastly, clear rules on things that are going to jack up the utilities, such as the space heater that kept one roommate's room at a constant 80 degrees F.

After being a recent divorcee, one of my guy friends asked if I could use a roommate to help pay for the expense of an apartment I couldn't afford on my own. We're good friends but we don't need to be in each other's business, plus he's just as neat and tidy (if not more) than myself. I guess my only qualm would be that he leaves my dishes and silverware in his room. hahaha... It's always important to lay down some ground rules but make sure to pick your battles. Like I'll do his dishes if I'm already doing mine, and vice versa. And never leave the coffee pot empty in the morning.

Cat AND ferret?! I've been terribly lucky to have friendly, normal, generally tidy roomies/partners while renting.

I'd sleep under my desk at work and shower in the gym before taking in a roommate. I just don't think I could handle it; college dorm mates were bad enough and we were all young and easygoing then. Now, not so much.

All those practical considerations are a given, but they don't guarantee a good fit. I believe in going with your gut. I met my first and last roommate through a mutual friend at a party. We hit it off incredibly well. I just got a really great vibe off him. A month or so later, my husband and I heard that his roommates were moving out of the house they all rented together, and we had a chance to move in. We'd never lived with a roommate before, but the house was pretty cool, and like I said, we just had a really good feeling about our potential roommate.

We lived happily together for ten years, even after our first child was born. Ultimately, our awesome arrangement ended when I got pregnant again and we all realized that we couldn't squeeze another body into our space. We were all sad at having to bust up our funny little family, but we're still close friends.

My roommates have to be clean and considerate. I've had roommates that have the same sort of working hours as me (8-5) and roommates who work evenings. Both were nice for different reasons.

I'd rather live in a closet than have a roommate.

In college, I had a roommate that was afraid of the dark, so she insisted on leaving a light on to fall asleep to. Which meant no sleep for me. I thought I could never live with another person until my next roommate who was amazing and considerate. I share a 2 bedroom with a friend now and she and I get along stupendously.
Being alone is alright for a weekend or so, but when I am left to my own devices I start...crying all the time? It's weird.

To continue my above comment re: "Not Insane" - Most of the room mates that I've had who turned out to be nut cases were recommendations from mutual friends! People who I knew through others! Yeah, on the outside they seemed fairly normal- working, educated, socialized.... but behind the four walls? Whoa! They say one never really knows another until you've lived with them. Yep. So true. Hey, my hubby is awesome, I totally love him, but living with him is way different from when we were dating! LOL!

Find the busiest person you know, someone who travels a lot: perfect.

I struggle to pay rent alone, I can have up to 2 roomies , still prefer not to, i m used to my privacy and ways ....

I'd rather live in a closet. I cannot do roomies. After living with me for a while my most patient friends would want to throttle me. I'm too persnickety. I cannot justify inflicting myself on my friends. Really, it's best for me to live alone, as I have too many anxiety issues and need the alone time, besides, I'm too set in my ways.