To get your arm stronger, the best way to practice is to throw the baseballfor ten minutes every day. I throw it for twenty minutes three times a week, which is pretty good. You do not want to go from not playing at all to playing ten minutes every day. Also, you can go to the batting cages if you want to hit better, or you can hit balls all the time at any baseball diamond. When I have free time, I always, go to the batting cages, go out and throw, or go to a field and play. These are the best ways to practice baseball.