disciplining shih tzus?

This dog is the pack leader in your relationship. You need to work on his discipline in all areas to make him know that you are the boss and not him. Try doing a bit of obedience work with him, giving him lots of praise for success, keep the sessions short and fun, stop if you find yourself losing patience.

Does he like being groomed except when you do his legs? If so, you just need to be firm with him when you get to the legs. Keep your voice very calm because if you're not calm, he won't be either. If he tries to snap, firmly tell him no and continue brushing. You need to be persistent and calm and he should accept brushing.

As for the leash, make him sit before you put it on. Crouch down so you're at his level and clip the leash on. Quietly reassure him and if he tries to bite, tell him no very firmly and continue. This dog just seems to need firm leadership so he doesn't think he makes the decisions.

I don't know about shih tzus in particular, but from experience with other types of dogs, I can tell you that a quick yell in an angry voice sometimes works. If he doesn't respond to that, threaten violence in a way he understands, like smacking the floor so the bang scares him.

If he doesn't react to that, you'll probably have to actually hit him. I would never hit an animal hard, but I've found that a bonk on the nose can be effective. If you accompany it with a fake smacking sound, he'll learn to associate them, and it'll make the threat of violence more effective later, so you won't have to really hit him more than the first couple of times.

I have a shih puppy and since he is so social his best punishment is when I leave him alone. Also I taught my dog to like grooming by giving him a treat he has to work on for a bit and while he is chewing I work his areas he doenst like me touching its worked so far and he is almost completely comfortable with the whole grooming process.

You should try crating him everty time he does something he's not supposed to.He'll get the point after a while!