What can be done to reduce the cheating?
Sore spot in junior competitive tennis in all regions is cheating, poor sportsmanship, rudeness. I've seen it in parents who coach their kids using hand signals, foreign language, whispers behind the fence.. I've seen 11 yr olds being mean and nasty to the opponent from the very moment they're called onto the court. It quickly degenerates to bad calls, in-your-face attitude, contesting every call, etc... The game no longer becomes fun, but more like a street fight against a thug.
What are some ideas to promote better sportsmanship?
I think it starts with better education. USTA should come up with a very clear Code of Conduct. Parents and players must read and sign it before registering for any tournament. Directors should post it at the check-in desk. Refs should be enforcing it with the appropriate penalties. Coaches need to stress that they don't need to cheat to win.
Everyone wants to see a good, fair, honest match where both players bring their best tennis. No one wants to go home feeling cheated. Parents - please stay out of your kids' matches. Players - please, please, just play tennis and leave all that other junk behind.