When it comes to getting rid of unneeded possessions, I'm all for diligently weeding through a home room by room. However, sometimes spontaneous decisions can be your best friend: if you know you'll never want the item in your hand, put it immediately into the appropriate outbox and never have to deal with it again. Here's a list of the sorting boxes/shelves/heaps I keep going at all times, so I always have a place to stick "junk" without a moment's hesitation:
Garage Sale Box: At this point, is really more of a garage sale heap, but you get my point. The moment one of us realizes we don't want something or won't use something, onto the heap it goes (using my Garage Sale? Garage Sale! trick as needed). This may sound ungrateful, but this rule holds even with things we just received. If a sweet neighbor gives us a truly hideous vase, I don't want to find a place to store it for a while, or even put it down. Instead, I'll be touched by our neighbor's goodness and thoughtfulness, and put the vase immediately into the garage sale box.
Donation Box: You may choose to have either a sale or donation box, but I like to have both. There are tons of little things that people might still get some value out of, but I don't necessarily want a bunch of 10¢ bits and pieces making our garage sale seem junkier than it is. This box is for all of the things I can't imagine someone going out of their way to buy, but that are not yet ready to be thrown away or recycled. After the garage sale, everything left unsold will go into this box, too.
Friend/Family Box: Perhaps you give your niece all of your hand-me-downs, or you bring all of your magazines to your dad once you've read them. Start a box with that person's name on it, and toss things in for them the moment you realize you'll never wear that dress again or the second you finish this month's Wired. Don't put it back where you got it or you'll have to go through all of this again later!
Rags/Fabric Recycling: Now that we all know how to recycle our unwanted fabric, I've set aside a shelf in our laundry room for clean, worn-out fabrics. Some of the ratty towels, shredded t-shirts, and hole-ridden socks will be used again as rags before we make the trip to our nearest recycling box, so we'll just wash and dry them again.
Electronics Recycling: We can recycle our electronics in the next town over, so I started a box to fill until we have enough recyclables to warrant the trip. Anytime we come across a completely broken/out-of-date/otherwise useless piece of electronics, we immediately throw it in the box. We also throw in our used up batteries and ink cartridges, though we have to drop those off at a different facility.
What helps you get rid of things?