I also have a hard time keeping my head down. When I was a junior the golf pro really harped on me for that, and still I can’t seem to lose the temptation to try to follow the ball, which opens up the club face on the follow-through. He told me to try to keep my head still and pivot on my neck like an axle. Then when the follow-through is done, look up and find your ball. When I can discipline myself to do this, I find it helps a lot.