The best way to read greens is through experience, I like to take eight balls and roll them to a hole at different speeds and on different lines, then with the eighth ball I putt it by picking the best speed and line to get the ball in the hole
Swing two clubs parallel to each other back and forth trying to keep the clubs from clanging together, this works your timing as well as coordinates your body with your arms
Help kids fix their slice by standing in front of them while they take practice swings and have them release their downswing straight down the line toward you