Scraps. I dislike wasting anything. I am still looking for the perfect system. I recently took a class offered by my guild titled "Managing Your Scraps". Not! She showed us how to sew random scraps together to make a block! Then, make a mug rug or glasses case or hot pad. Waste of money, but fun day with others. I do love my new glasses case, but I did not need to pay for "how to use your scraps"!
My scraps are large because I over-order for projects. (Ran out of fabric once-never again). My fabrics are difficult to sort by color - they generally are blue with lots of other colors. Since I like applique, I have a tub of solids; another tub with pieces larger than fat quarters; another with pieces more the size of my hand. Smaller pieces get tossed without guilt!
My first scrappy quilt was red roses with green scraps surrounding. I literally had to buy fat quarters in order to make because I had no green or red fabric!-I do now!