When you purchase something, pay attention to how it looks when it comes out of the box or package. It is likely that the key to storing it in a nice neat way is how it was when you bought it. Think about a fitted sheet. Folding them seem impossible but when they are in the package at the store they are folded neatly with uniform corners and a perfect square shape.
p.s. If you wonder how to fold a fitted sheet, Marsha Stewart has a YouTube video that can teach you how. Just search "fitted sheet Martha" on YouTube.