Nipping… depends on when the “nips” occur. If during play, remove your hand, gently hold pup’s muzzle closed and say “no bite”. Repeat as needed. If what used to be a nip is replaced by a slurp.. that a “Good No Bite” with a big smile and nice pat. If it’s a nip when being fed, then it’s a “NO” and repeat with food held between your first 3 fingers, and either a calm, quiet “Easy” or “Be Nice”. Never drop food on the floor for the dog to eat, and NEVER toss treats for them to catch in the air … at least not before “Easy” is mastered. Even then, I discourage it because it encourages snapping.