Attention and Control
A. Start with keeping control when he’s on leash! Have rewarding play sessions with your dog on leash with their focus on you. By keeping them on leash at first you’re minimizing their chances to mess up. After they pay good attention on leash and aren’t yanking, drop the leash in a quiet, controlled environment and play focus games. Move up the criteria from there until you can get their attention no matter the distraction, with the leash off!
Be rewarding for your dog at random intervals, in many settings. I like to think of it as a slot machine for your dog. He pays attention many times, and you reward him when you see him doing it, in many different ways. Sometimes it’s a pat on the head, sometimes a cookie or a walk.