Don’t chase your horse; he can run faster. Walk slowly and speak softly.
If you are going to walk behind a horse, make sure he knows you are there. Speak softly.
A horse can tell if you know what you are doing; and he can happily give you a hard time if you don’t.
A horse is an emotional creature. Build a relationship with him. If he likes you and trusts you he will give his very best for you. You can’t do this instantly; it takes time.