By color, is by far what works best for me. I do it by the good old color wheel. Reds, oranges, yellows, greens, blues, violets, purples, B&W.
Each stack is then sorted from lightest on top to darkest on bottom, like -
pinks
reds
burgundys in one stack or two depending on how much you have and the space to put it in.
it is easy to see all the colors and go to just what I want. I do keep cheaters , panels and baby prints seperate.
peace