Directions: Grab a piece of tissue. Have your child take a deep breath, hold the tissue about an inch from his face, and see if he can move it by blowing the air from his nose. You can also demonstrate how to blow, and then give the tissue to your child so he can try.
Each time you practice blowing with your child, he learns to apply more and more force, keeping his mouth closed, which is the hardest concept in learning to blow.