When coaching baseball pitchers please pay attention to how arm mechanics can add or reduce stress to the elbow and shoulder depending on the path taken from the breaking of the hands from the glove to release. This video from the iBook, Practice Baseball to Win, is 1 of 2 outlining the checkpoints to consider.
When coaching baseball throwing, the grip is important and probably the most often overlooked. Start with an explanation and do a “grip check” regularly. This video from the iBook, Practice Baseball to Win, covers, grip check, and is step 1 in a series covering the basics.