I usually just divide fabrics into light and dark and go from there - just grabbing a fabric from either stack depending on the need - the contrast makes more difference than whether or not the fabrics actually go with one another. After the quilt top is assembled, the contrast is what stands out. That being said, I'm currently working on a pinwheel scrap quilt and am having a blast picking out a specific light and dark for each of the pinwheels - and I'm taking way too much time putting together beautiful combinations. As mentioned, I don't usually spend that much time coordinating scraps but this is an exception. Love putting all my little dibs and dabs of scraps together into quilts! Have fun!!