Learning not to touch is essential.
"Don't touch," "leave it," "NO." How many times have you either belted one of these or something similar? How many times have you heard these or other phrases of humans pleading to our canines? Hahahahaha, too many times. How on earth do you teach a dog not to touch? Easy. Don't let them. Yep, it is as simple as that.
Of course it takes consistent training; and any little slip in the wrong direction from you, may lead them down the slippery slope to touching again. Just the other day I was so very impressed with Elsa at the park. We were in the midst of a great chuck it retrieve session when a rabbit appeared from the bushes behind me. As Elsa got closer to me her ears shot up and her body tensed. "Leave it," I automatically said. She stood statue still with the ball in her mouth. There was a ponder moment from her; to chase or not to chase, that was the question. She chose not to chase which is huge for a dog with high drive. I immediately chucked the ball out as far as I could to reward her.
I have been working hard on the rabbit thing over the years. Of course Elsa wants to chase them but I have attempted to make them a non issue. The ball is much more fun and if she stays focused on it; "it" will continually be thrown.
Once a dog understands "leave it" then you can implement it with just about anything. Nice. But what about when they don't know "leave it" yet? I have trained many, many puppies who don't know much of anything when we start out. When you don't have any formal communication sounds or verbal cues to fall back on you need to step in.
I remember working with several puppies who were having a very difficult time understanding that they were not to eat from the adult dog's bowl. They needed to learn the rule quickly because I was going to leave and their guardian needed control of the eating situation. I do not like free for all, chaos eating and I also do not like having to separate dogs while they eat; so they must learn the rules of eating.
Puppies are stopped in their tracks. That's it, that's all. No passing, wherever the line is made. This means physically being prepared to stop them. This is not something that can be worked on willy nilly; you must be fully aware, highly alert and ready to stop. One breach of security and you're sunk. If you let your puppy get passed you then they will keep trying forever. Typically puppies learn very quickly that they are not getting by you. Oh they will try, those little smarties try to deek around you but you must be faster than them.
I ABSOLUTELY LOVE the moment of realization. The very specific point in time when they stop trying. Even when their own bowl of food sits on the floor; a puppy often desires what the big dog is eating. Their reward for not trying to get the food from the adult is their own bowl of food.
Utilizing your arms and legs is essential in teaching dogs not to touch. You need to stop them at all costs which often involves feet and hands. You may feel inadequate tackling the job of just not letting them; but if you want to make sure that they understand "not to touch," you must make it very clear to them. If it is cloudy at all, you're sunk.