Thats a good question nspeltz11 and a complicated question.
Try to identify the type of pitcher you are and the type of mechanics you have and find an mlb pitcher with a similar delivery. An important thing to think about is that we are all different and require unique checkpoints throughout our deliveries. So trying to copy another persons mechanics might not give YOU the best results. If you're watching video of a pro, find checkpoints that include balance, head position, direction(glove side), lower half shift, height throughout the pitch, and balance at the end. Watch how it all works together with rhythm then try to find that for yourself. Look for the same things when your analyzing your own video. It should all be smooth, balanced, and repeatable. Check out this article for how to work efficiently.
Keep me posted on how its going. Try to find more than one MLB to watch, see how they are different yet work the same with common checkpoints. Hope this helps.