I don't know about you, but my closet doors are usually open when I'm in my bedroom; I'm in and out of there all the time looking for something. But most of us don't realize that, try as we might, guests occasionally get a peak at the "internal organs" of our closets. So, we might as well have them work for us!
If your room is small and wallpapered, you can expand the visual size of it by wallpapering the interior walls of your closets with the room's wallpaper. It's a subtle reminder that there's square footage beyond those doors. And, this trick will work for any room in the house. Of course, if your closet is jam-packed, it won't be very successful. Unfilled closets, such as front hall coat closets, are perfect guinea pigs for wallpaper. Do any of you have wallpapered closets?