When I said I separated my scraps by size and value I should have added that that is only for pieces that I have turned into "pre cuts". My "pre cuts" are in two drawers one for solids or prints that read as solids and one for prints. Each drawer is large enough that I can store stacks of 5", 3.5" and 2" squares separated into light medium and dark values. I also keep leftover commercial precuts and strips in these two drawers mixed in with my homemade precuts.
anything too small to get at least a 2" square goes into my shoebox for string quilts or making crumb fabric-- that's just a jumble. When the box gets too full to close I spend some time making string blocks or crumb fabric to put into a scrappy quilt.
If a scrap is fat quarter sized and intact (no holes) it gets folded around a template and put into my fat quarter drawer on end with the fold up so I can see what I've got as soon as the drawer is opened. Any intact pieces that are larger than a fat quarter but less than one yard get wrapped around cardboard and placed in another drawer fold side up.
Since my my sewing space is so small (8.5' x 8.5') I have to keep the scraps organized or they'd take over my work space.
I bet if I kept track I'd find that I spend way more time sewing with scraps than with my other fabrics-- it takes a lot of time to keep on top of them.
Rob