BaseballAg, just play catch with it. Depending on the age of your son, you may wish to begin with an incrediball. Throw him grounders, he will learn to catch them two handed (alligator jaws), throw him line drives and he will learn great transfer mechanics. Basically, the soft hands trainer will teach your son to catch a baseball much like one catches a basketball; stop the forward movement of the ball with the glove hand and keep the ball from falling with the throwing hand. If you have two of them you can play a game of rapid fire to see who misses first, or if you don't have two, use the backside of your glove as your softhands trainer.
On grounders, the trainer will teach you to use your throwing hand to protect your face, then to trap the ball to keep it from coming out of the glove, then to get the handle on the ball and come out of the glove ready to throw.
On line drives, the softhands trainer will teach you to follow the ball into the glove with your throwing hand, get a handle on the ball and come out ready to throw.
They are good training devices.