Here's something you actually can change. If you masturbate a couple of times a day, chances are you aren't going to ejaculate very much semen, or ejaculate very forcefully. But if you want a more impressive ejaculation, hold back and save it up for a few days or a week. Drink a lot of water during the 6-hour period before you masturbate, and then draw out your masturbation session for as long as possible, spending a lot of time being very aroused. When you do finally ejaculate, it will probably come out with a lot more force, and there will be much more of it than usual. Plus, it'll feel way better than the average orgasm.