Although I'm doing well, I don't think I fully know the winning formula yet. It's going to take time.
It's all about training. Pick a position or a small group where you want to concentrate on improving for an entire season. This will probably be determined by the players you have. Higher the potential, ie Superstar or better, easier to improve and train. For example, let's say you have a Superstar or MVP potential Shooting Guard. Well, I would do everything in my power to train that person. So, Jump Shot, outside shooting, Perimeter Defense, etc. Then for the other positions, purchase older but skillful players to fill in that role. So, if you're training your shooting guards, for Power Forward and Center, then purchase a 30 some year old player that has some skills.
Other than that, I say you have way too many players on your roster. Cut some of your benchwarmers, etc.