This takes a little carpentry but works for everything. Cut 1 by 12 planks in 16 by 16 inch pieces. Actually any size will do, depending on that you want on them. Using four of the pieces, screw ends together and you have a nice square. Make lots of them and stack them in any configuration you like and then place the shoes on each "shelf." We have used these for lots of different storage issues. My daughter has a bunch of these stacked in her living room for a nice bookcase and place for knick knacks. They look great , modern and neat.
You can make different sizes, paint them, clear finish them--whatever suits you.