You guys know how a toothbrush has that blue indicator strip that turns white when it's time to change your toothbrush?
I do the same thing with the hubby's towels.
I stack them in the closet with the new, white ones on top and the old, blue ones on the bottom. When I see a blue towel hanging on his towel hook I know it's time to wash towels. It's the little things that make you a genius, right?