It's important for coaches to be able to identify incorrect throwing mechanics in their squad, and not just for the pitchers. Sloppy mechanics can lead to bad throws--and even worse--possible injury.
Here's a quick drill you can use to train your players the right way to throw.
How to Easily Spot Bad Mechanics
If a player's throwing mechanics are improper, one characteristic of this is the glove hand flying out away from the body and away from the target. This will result in less velocity toward the target and generally a ball that is offline.Look for this in practice from time to time.
One drill I use a lot to improve throwing mechanics is to place three balls into the players' hands (glove hands) and have them go through their throwing motion. Note: If the glove hand is flying out, the players will not be able to hold onto the balls in her glove hand and they will fly out.
This produces instant feedback to the player that a mechanical correction is needed and the coach can correct it immediately. (Giving the player the chance to quickly assess the problem and make adjustments.)
If her mechanics are correct, the balls will be held in the glove hand and no correction is needed.