Use magnets to find nail holes
You may gradually get the urge to paint your house or replace the wallpaper in some area. When that time comes, you’ll need to remove anything hanging from those walls, but what should you do when it’s time to restore everything?
You could, of course, make brand-new holes. However, you might also fill the existing ones with little nails before painting/wallpapering them. Then, after you’re finished, use a magnet to discover and reuse the very same ones on the wall.