Keep one in the shower filled with a mixture of half vinegar and half Dawn dishsoap. Use it to wipe down the shower while you are in there and your shower will always be clean. I keep hearing that this is the magic formula!
Over time, towels build up detergent and fabric softener, leaving them unable to absorb as much water and smelling funky. Recharge them by washing them as indicated on picture. This strips the residue and leaves them fresh and able to absorb more water again.
Better Than Salt Dough (Homemade Clay for Ornaments or Handprints)