Some great suggestions! Think too, of it this way: What payoff is he yearning for AND getting when he's pulling and you're continuing to walk along behind him? He's wanting....in the worst way to go forward and se the big, wide world. He can hardly contain himself, he wants it so much. He'd drag a house behind him if he could to get to where he's going.....forward. Remove that payoff/reward for that pulling behavior. Remove forward motion. Don't let it happen for one more step.
Now, what can you think of to give him as an alternative behavior for which he CAN be rewarded. What reward is equal to or better than that pulling forward and getting where he wants to get? Well, first, you're going to have to teach him an alternate way to move forward which you will reward him for with a VERY SPECIAL treat and a very cheerful voice. So, you first stop moving forward, stand strong. Show him you're not budging. Stand for as long as it takes for him to wonder what the heck you're doing. He'll look back and probably take a step or two toward you, putting slack in the leash. At that point, resume walking. He'll again pull. You turn and walk the other way. You make all kinds of random turns so he doesn't anticipate where you're going. He'll pay better attention to you. When you turn, be careful not to hurt his neck. Whenever there is a moment of slack in the leash or he's closer to you, praise and pop a treat in his mouth while you're walking. Don't stop or wait. Treat him immediately when he's doing the behavior you like. After he improves a little bit, try walking in a straight line and see if he'll cooperate. If he takes so much as 3 steps along side you without pulling, reward him. Show him that where he is (next to you) is what you like and what will bring him a GREAT reward. A clicker is great. You can mark exactly where he is with the click so he knows precisely what it is you're talking about. Without it, you've got to be quick with popping the treat in his mouth.
All in all, make it worth his while to walk nicely. Make it fun, enjoyable, tasty (yum yum) and forward moving WHEN he complies. Don't provide the fun of walking forward or the left over steak tid bits or the happy, playful praise when he pulls. He'll figure out ON HIS OWN (using his OWN brain) what way of walking is more beneficial to him. You'll have to remember to make the reward better than the reward he gets from pulling.
Practice in the least amount of distractions you can for a while. That helps too.
Teach him also, "watch me." eye contact=treat. Use that when you're walking once he learns.
Nothing in training happens overnight with a pup. It takes practice like absolutely everything in life. If anyone says that you get a trained dog quickly by yanking their collars or scolding, don't buy into that. They may demonstrate behaviors quicker when they're broken down in spirit, but is that worth it? I'd much rather have a dog who enjoys learning and is happy when he accomplishes new skills. I also like a dog who is encouraged to use his own head, given a choice and not be forced into doing something. (I make the choice he is going to choose the one I want him to choose. s-h-h-h....don't tell him)
