Miriam and Katrina discovered this method while on tour with their children's choir this summer.
1) Spritz the wrinkles and fold lines with a spray bottle.
2) With a blow dryer, blow dry.
This works best with lightly wrinkled polyester and polyester blends.
For heavily wrinkled, or cotton clothes, spritz and tumble in a clothes dryer with a clean dry towel for 5 minutes.