One of the more annoying things to store is seamless paper backdrops. They are big, bulky and you can't lay them on the flow because they will collapse over their own weight and great folds. This means that the best way to store a seamless paper is vertically.
If you have a long wall that is unused (as no studios probably have), you can stick em on the wall with something like this foam system. Here is a much cooler way tough.
Photographer Rob Grimm made a rope and dowel system that can store a few dozens of backdrops in a neat and orderly fashion. Check out his video below.
