Cut the detergent: Soap residue stiffens towels, so minimize it. With a high-efficiency washing machine, you need no more than 2 TBS of mild detergent per full load. Use bleach only when battling stains; frequent use will break down the towels’ fibers. When towels begin to feel stiff, you can break down the soap residue that is to blame, by adding non-toxic white vinegar or borax to the next wash. Using less detergent and bleach is better for your towels, your wallet and the environment.