When you throw put the most force in the very end of your arm, all the way to your fingertips. That way the ball has this last push and all the force is exerted at the very end which almost amplifies the force that you put on the ball. First relax your body. Relaxing is key. It makes your body respond faster. Then when you pitch the ball keep it relaxed all the way until that last second then tighten up and give it all you got.
I read a proven article and its very accurate. They say that when you imagine yourself doing something that you aim for, you can make it happen. But do not only use that you need to practice too!