I would recommend trying the halti. I have never used it myself but numerous people have and had great success with it. I personally do things the long way but it really teaches the dogs to walk nice on a loose leash.

I do the stand like a tree method. If the dog is pulling I stop dead in my tracks and won't move. The dog is pulling to get somewhere faster, right? When you stop dead in the tracks they don't go anywhere. When the let up on the leash and look at me, I praise, give a treat and then walk again. At first you don't go very far. I mean sometimes we don't even get 5 feet in 1/2 hour. Eventually they learn to associate that it is the pulling that stops the walk!

This method takes a lot of patience but once the dog learns you will have the nicest walking partner around.