A good softball pitch has three basic stages that you must master in order to throw the ball accurately and effectively. The three main elements of a fast softball pitch are how fast the pitcher drives off the rubber; reaching back after the down-swing; and pushing back on the stride leg. Keep in mind that while you can practice your pitching as much as you want, the best way to improve your technique is to hire a pitching coach.
Spring off your push-off leg. While a long stride is also important, speed as you push off is necessary, too.
Reach back with your pitching arm, creating a large circle. When you get halfway around the circle, tilt just the upper part of your body backwards a bit. While you do this, reach back towards second base. This will allow your arm to whip around better, giving you more energy for you to release the pitch.
Stand tall as you pitch the ball. You'll want your stride leg solid, your upper body erect and your overall body strong.
Experiment with variations on a basic softball pitching stance. Try to start your pitch while bending, crouching or standing straight up. Vary how far back you swing your arm and how much you pivot off your back foot. Ultimately, you want to find the combination of mechanics that will work best for you and make your personal pitch faster.
Concentrate on your body while you're pitching. To master the mechanics and techniques that work best for you, you must develop muscle memory. This will happen if your mind and body are on the same track while you pitch.
Practice regularly and frequently. Try to practice at least every week. When you find a pitching technique that works for you, perfect it. Don't try to find a new technique, but instead master the one that seems to be working best for you.