What I would do is train the dog. If you rely on the prong collar only, you will always have to use it. In that sense the dog is never trained. The "tree" method will work faster if you use treats. I don't stop whenever there is just "tension" on the leash, but if my dog lunges ahead and jerks me with him, then I stop short and he can't reach that tree or whatever he was trying to get to. Then when he just looks at me, I use a bridge word, which serves the same function as a clicker but I don't have to actually carry a clicker with me. I used "Ja", since it was a word the dog never heard anywhere else, and as soon as he made eye contact with me, whether the leash was loose or not, I said Ja, and then gave him a treat. Eventually he learned that was how to get the treat and would immediately look at me, then he started coming toward me to get the treat, which made the leash loose, so as soon as he ate the treat we started again. This worked relatively fast for me, but all dogs are different.