Here's a tip for folding fabric of all sizes to make uniform stacks:
Use a 6″ by 24″ quilting ruler and roll your fabric on it.
Lay your fabric out on the table. This works for new fabric as well as larger leftovers. Place the ruler on one end and roll away. Slip the ruler out and fold the roll in half.
All fabric is the same width, some of the stacks are thicker. I have been working at my stash, sorting by type of fabric. The stacks sit neatly on the shelf. I'll post some photos when I get a little further in the process...