First, pieces of at least fat quarter size are kept on shelves. For pieces smaller than that, I keep strips at least 1 inch wide if they are width of fabric. The rest of the scraps get cut into 5", 3-1/2" or 2" squares, which I store in clear plastic shoe boxes. I often raid the boxes to find that perfect little piece for a paper pieced square or other small project. Someday, I'll tackle a certain scrap quilt I have in mind, but there is a lot of sorting to do first....