A crumb quilt is what I had always called a crazy quilt. I always use a base fabric square. Starting in the middle with any size or shape fabric, build around the center fabric until the base is completely covered. Then, trim to size. I'm sure someone else will come up with better instructions. The idea is to use up the smallest scrap of fabric. I like to use all different colors, solids, prints, checks, plaids, stripes, anything goes.