How many games do you play a week? If you are playing about twice per week then 2 nights of practice should be enough. What about getting some scimmages where you could stop play when you need to to give instruction? I have found that to be helpful. No matter what remember that kids play sports to have fun. Try to make it fun for them(and you) win or lose. Sometimes it helps to do something as a team other than playing ball. Bowling, movies, etc.. can help build team. The Globetrotters are coming to town-that would be a fun outing.