Start training a puppy not to bite by first teaching it bite inhibition. Allow the puppy to mouth on the hands during play until it bites too hard. When this happens, immediately give a high-pitched yelp and let the hand go limp as if it is hurt, much like puppies do when playing together to indicate that the offender is playing too roughly.
When the puppy releases or licks the hand instead of biting during bite inhibition training, praise it for its good behavior. The steps of the training should be repeated no more than two to three times in a 15-minute period. If the training has no effect, switch to a time-out procedure. During the time-out procedure, yelp loudly when the puppy bites, remove the hand from the puppy's mouth, and ignore the animal for 10 to 20 seconds. Immediately get up and walk away for 10 to 20 seconds if the puppy bites the hand again. Return to the puppy when the time is up, and begin interacting with it once more until it bites, then repeat the process. It is important to distract puppies that have the habit of biting when they are stroked, patted or scratched. Do this by giving the puppy a toy or chew bone to bite instead, or by feeding the puppy treats while it is being rubbed.