light blockers on the outside with sheers on the inside for the days that you wanna pull back the light blockers and have the light filter through the sheers.

Doesn't actually matter. But I'd put the light blockers on the inside (closest to the window).

It's like when you stay at a hotel. Light blockers on the outside, sheers on the inside for when it's light out and you don't want people to be able to see directly in your window.

We have them the opposite way, sheers closest to the windows, as these are almost always drawn, and thicker decorative (and light blocking) curtains further away from the window. These are over a patio door in our bedroom so during the day we usually have the thicker ones pinned back and they frame the sheers.

i'm with sillahee...that way, you don't have to reach behind the sheers to pull open the light-blocking curtains; plus when they're open, the light-blocking curtains will frame the sheers.

What types of curtains are you dealing with?

If your light-blocking curtains are also decorative and you would like to see them, hang them on the outer rod. You can leave the inner rod empty, or hang sheers on that. Sheers can be useful for daytime privacy if you need it.

If your light-blocking curtains are those plain white or off-white curtains with a primary purpose of being light-blocking, you can hang them on the outer rod if you like they way they look.

But if you'd rather have a more colorful curtain, hang the plain light-blocking ones on the inner rod, and your decorative curtains on the outer rod.

It doesn't really matter where they are hung in terms of their light-blocking ability. What's more important is that they cover the entire window, including a few extra inches on each side of the window, and preferably on the top and bottom as well, to keep light from leaking in.

If you don't want to bother with light-blocking curtains, there are a variety of shades that block the light. Those work best if they are outside-mounted, but if you want to mount them inside the window frame, you can use a thick curtain to block the light that will come in around the edges.

it is traditionally light blocking curtains over sheers. in fact, i've never seen it any other way. if you look at double pole brackets, the inner pole is thinner than the outer pole because it only has to support lighter sheers.

It really depends on what the light blockers look like. We had a set that were very good at blocking light, nothing came through those babies. But they were plain utilitarian white. So they were hung next to the window with decorative curtains facing the room. However if you can find attractive light blocking curtains then you could do it however you prefer.

Until you settle this, invest in sleep masks for the both of you. They've transformed my sleep. Good luck resolving the curtain matter.

Another vote for light-blockers on the outside, sheers closest to the windows so you don't have to mess with them as much. Sheers can get snagged on the curtain rods pretty easily, you want to leave them be as much as you can.

Maison21 is correct - the thinner inner rod is for sheers and the outer, larger diameter rod for thicker curtains.
A dark color outer curtain will usually block a significant amount of light, but if you want it absolutely dark, you can use drapery hooks to add a black out lining to your outer curtain by securing the lining to the upper hem of the decorative curtain panel.

It's always sheers inside closest to the window, with the thicker curtains on the outside.

Yes, the sheers should go closest to the windows.

Depends, I'd say. If it's a light blocking decorative curtain, I'd put it on the outside. If it's just the white material, then inside! If there are sheers involved in this scenario, they go on the inside.

It depends on how finicky you are about looks vs function. Ideally, you would have double rods that WRAP AROUND THE SIDES so when the outer (light blocking) curtains are fully drawn there is no gap to let light in. Think to how hotel room windows are.

Having two layers allows you to have sheers which are great in a bedroom because then you can let the daylight in and not worry about people seeing you in your skivvies during the day.

If the current double rods leave a large gap when you put the light blocking curtains on the outside rod, they may have to go on the inside rod, and you could put a valance up on the outside rod.

Actually, it does matter. Light will leak around the outside of the treatment. Think how an eclipse works when the moon moves in front of the dun. The center of the sun is blocked out, but all hte light around the sides is not. The closer the drape is to the window, the less light will leak out. an even better and cheaper alternative is a light blocking roller blind mounted inside the frame. You pull it down when needed and it disappears up when not. and you aren't stuck with the heavy light blocking drapes. If you do go with drapes, make sure you have light blocking as opposed to insulated; they are two different things. Good luck!

The sheers go closest to the window, and the heavy drapes hang outside the sheers.

I have never, ever, ever, in my life seen heavy drapes hanging next to a window, and sheers on the outside.

The only variation to this is if you put a light-blocking roller blind next to the window, between it and the sheers.

In our east facing bedroom, we have a light blocking roller blind on the inside of the window, a thick curtain on the outside (which blocks the sides, and helps insulate) and I'm planning to get a double rod so I can hang sheers in between. Everything covered!

Traditionally, you would put the blockout curtains in front so it covers the entire window, and then then sheers at the back so when you pull the blockouts back you get the light but keep your privacy. BUT, some people do put the sheers in front because they prefer a softer look or because they have a lovely sheer curtain they want to show off (and this can look stunning!). The most practical option is definitely sheers behind.

I'd agree with others have said, about the sheers going closer to the door. I think it would be easier when you go to open the light blocking curtains and just want the sheers for privacy.

My husband and I are total vampires and definitely feel for the importance of blocking out that early morning light. This is the hard core way (assuming that picture is your place and it's that type of window*).
To make sure you are blocking out as much light as possible, the curtain rod (and curtain) need to extend about 6-12" past the window on both sides. The more the better. The curtain rod also needs to be mounted several inches above the window. Finally, you'll need to put up a valance of some kind to get the light that will come in from the very top. Depending on the style of your house, you can find a valance that will work. We have a modern house and use valances that are just straight aross. This is how all the hotels do it and we've learned from them! It works!!! Because most curtain rods will sit at least 4" from your wall, without a valance you will always get light seeping in from the top.

*if you have windows that aren't so big, sometimes shades work better than curtains. Either a snug fitting inside mount or an outside mount with plenty of extra room to cover all four sides.

Sorry for the long answer. We are totally passionate about blackout rooms for good sleep!

No matter which order you chose to hang light-blocking curtains in, if you want them to work, they have to sit outside of the window frame to avoid light-leakage around the sides. The only thing I've seen that works to block light inside a window frame is a light-blocking shade that has tracks on the sides like this to prevent light-leakage:
http://www.comfortex.com/images/Product%20Shots/slumbershades/SlumberShadeTrackBelow-NoFuzz.jpg

Amanda, here. Thanks, all, for the suggestions! I was originally thinking of having the sheers on the outside, as I was worried about the light blocking ones being too heavy for the room. But, we opted to hang our sheer whites on the inside closest to the windows and our thick, dreamy gray curtains on the outside. Our bedroom has a lovely, sleep-inducing cocoon feeling now.

To me, this is a no-brainer, especially if you've ever in your life stayed in a hotel. Sheers are just that: sheer. Why would one put see-through curtains over another curtain?