What do I do about stiff jeans and towels?

Read about the benefits of vinegar above.

Alternatively, a quick run through the dryer or a hard shake before hanging fluffs clothes up. Even towels will stay soft after they're hung to dry. They just need to be in the dryer long enough to get them puffed up. The dryer does need to be set on a heat setting, and it's a short amount of time.