Like many of you, I never pre-cut either. I save every scrap by color, and sort by size as well. I do applique and those bins are my go-to supply of bits and pieces for applique, without having to cut up other fabric. It would be just my luck to find a great fabric that I need 5" square blocks, and have cut them to 4"! I don't tend to do scrappy quilts, so no sense in pre-cutting scraps for me!