Tap the index and middle fingers on the hips. Imagine motioning towards the diaper snaps.
Place the hand under the chin and wiggle the fingers.
Form the signed letter X with both hands. Place one fist on top of the other fist. Then switch the hands.
Beyer, Monica. 2006. Baby talk: A guide to using basic sign language to communicate with your baby. New York: Jeremy P. Tarcher/Penguin.