Learn how individual joints move. Remember that relaxing and holding are just as important as contracting and extending, and ALL joints are important. Abs, neck, ankles, wrist, all can and will make a fight. Learn how pecs and glutes change how your punches and kicks work, and remember that sometimes relaxing will make your punches go faster than contracting pecs. Raising and lowering your arms is sometimes less effective than just relaxing your shoulders and letting your hits fall where they naturally would.
Don't use starters made by other people if you want to become better at the game, and never use starters that you can't modify for precision.