I completely agree with what you said about the right thing easy and the wrong thing hard, but I think you got that part backwards :P
When the horse is doing the correct thing (walking) release all pressure, just be walking with the lead soft. When the horse STOPS apply pressure.
When teaching forward movement I like Gawani Ponyboy's "Horse, Follow Closely" Method.
He stands in front, slightly to one side of the horse (so as not to be in a trampling path in an emergency). Holds a long lead lead attached to the horse, he starts running the line through his hands, gently applying pressure, each time he runs his hands over the line he gradually increases the pressure. The whole time his body language is soft, his shoulders are soft and slightly askew, eyes gently resting on the horse's with a gentle look on his face. When the horse takes even one step forward the pressure is released and a soft word of praise is given. Then repeat until the horse is next to you. Practice this until the horse is walking willingly toward you until you can be walking backwards and the horse will follow unbreaking. Gradually you can turn yourself around and the horse will follow.
I forgot to mention one other fantastic training method "TIME" Spend time with the horse! As much as you can! You don't need to being doing something with him all the time, just take a book out to his paddock and enjoy his company. Spend time fussing on his mane, or brushing him, but not demanding anything of him. Just enjoy your time with him :)
I will definitely try the "time" method, though I don't think I'll be reading since I always have my uncle with me and he'll be bored. I'm 16 and he still fusses over me like I'm 6, but I'm not complaining! :)