John Gagnon says: Biting is completely normal in a puppy. It’s like a baby putting things in his mouth. You just kind of stop them from doing it, but you’re not going to scold a baby. So I definitely don’t want to punish a normal, healthy puppy behavior however inappropriate it may be. But I always carry things that are better for him to chew on, so I have rope toys everywhere. I will have chew bones or whatever it is everywhere I go, in every room in my house.
When my puppy and I are interacting, I will put a rope toy in his mouth. Tug of war is completely acceptable. It doesn’t make aggressive dogs. So I'll play tug with him or give him things to bite on. If he lets go of that and bites onto my hand, game is over. Biting me ends the game because you, the human, have to act like a real wimp. Stand up and cross your arms where he can’t get to them and turn your back. They might whine and cry and tug at your pant leg, but just ignore that until it stops. With enough repetition, he begins to realize that, "Wow, this guy really is a wimp" and "I can’t put my teeth on him because it ends the game and I don’t want the game to end." So, you just need some patience and lots of things that he can chew and bite on that are acceptable.