Another way to do a controlled scrappy is to just use two colors. A two color quilt can be made with two fabrics or dozens of fabrics in just two colors. I did one in red and ivory for my daughter in law that was just stunning. It's one of the few quilts I don't have any pictures of. The pattern was a star block. Each block had two different reds and 3 different ivories.
It does help to get over the matchy-matchy when doing a scrap quilt to just divide into lights and darks and throw in a bag and sew on whatever comes out of the bag next wheather it matches or not. Clashing fabric combos *really* give a scrap quilt life and personality. Pick a light/dark pattern and go for it!