Double Pane Windows?

My daughter got black out curtains for her bedroom windows and they work really well. They weren't expensive either. I don't remember where she got them, but probably either Bed, Bath, and Beyond or Target.

Honestly recessed wooden blinds do the job for me. The faux wood works just as well. Just RECESS them in the window frame instead of mounting them on the outside. You can get em at home depot for like $40 bucks a set (includes cost of cutting, which is typically free).

Unlike the typical plastic blinds, the wooden ones are FLAT. So when you close them they kind of make a flat little wall that doesn't let light through between the slats. Super easy to install. I did mine in like 15 minutes. You just need a drill.

If you really need to block the light and don't want black-out curtains you can cut a piece of cardboard (the presentation board stuff works well) and attach it to the window frame with Command velcro picture hangers. As an option you can cover the cardboard with aluminum foil which one of my friends swears by.

If you really need to block the light and don't want black-out curtains you can cut a piece of cardboard (the presentation board stuff works well) and attach it to the window frame with Command velcro picture hangers. As an option you can cover the cardboard with aluminum foil which one of my friends swears by.

This also works well if you're hiding from the government.

This also works well if you're hiding from the government.

But it works best if you also wear an aluminum foil hat!

I will say that the blackout curtains are so effective that you might want a way to pull them aside during times you're not sleeping. My D has brackets mounted on the wall on either side, so she pulls them over and the brackets hold them away from the window so she can have lovely natural light come into the room. And they look pretty also. You may not care about that, though. My D is a very talented decorator and that kind of stuff is important to her. She could have chosen interior design as a career, but she prefers to be a business tycoon. :)