@Duke:
JeepJeep - My little guy Duke was a nasty nipper when he was a pup until I took a different approach. Whenever he was doing something he shouldn't, I would call him with a happy voice - so inviting that he'd stop and come to me. (reverse psychology of sorts) I noticed that if I called him in a mad, mean voice - he'd get more aggressive with his behavior. I also rewarded him for coming to me with more happy talk / treat if I had one. Once he began to trust me, I could then begin to discourage unwanted behaviors with a "no". If I got no response from him, I'd roll up a newspaper and smack my hand or table with it. It makes a loud noise that Duke responded to and got the heck away from it. I never hit Duke with the paper though, just my hand or couch or table, somewhere near him. Can't hurt to try something else, there is bound to be something that will do the trick for you.
Ding, ding, ding! We have a winner! :D….great answer Jill! That is what I do as well. Or if a puppy has something they shouldn't, I walk up and say 'oh, you silly puppy....what do you have there...and I gently take away the item, then we do a tickle, gentle wrestle session';
Before I learned about better training methods, I found that after several times of say "NOOOOO" and ripping away what they had, it wasn't long before my approach caused the dog to get defensive right away.
I also would want to clarify what nipping means. If you take something away, and the dog gives you a little pinch with his teeth, IMO that is a doggy invitation to play. Now, if you go to get something they have, and they freeze, growl, eye-roll (some of you know exactly what I mean) and snap...that is not a nip...that is resource guarding, and needs some intervention. Nipping is to get your attention, and interaction....guarding is to say 'back off this is mine'....