One thing I would suggest is to play the name game. You said Buster wouldn't look at you when you called his name? What you should try is call his name and as soon as he looks at you mark it with "yes" or whatever verbal command you use, and give him a treat. Try it first for the first little while at home, where there aren't as many distractions and then eventually try it outside. Another thing you can teach him is heel. I taught Boss heel and "other" (which is him heeling on my right side). I would pat my left side and tell him heel, and as soon as he gets into the heel position, mark it with "yes" and then treat "good heel."