What Roger mentioned is good advice.
In addition, any and all movements by a pitcher is very personal and dependent on the physique of said pitcher(s). Your tall and slender pitchers will have a noticeable difference compared to stocky, muscular, and compacts. Add to that, aggressive pitchers in the drive forward can be very animated with their lower half compared to the pause-n-drive style of pitcher.
I mention all this based on mature, fully developed athletes - not youth or even high school varsity youngsters.
On this web site there are videos of many different professionals and their individual persuasions with regards to your question. Study some of these people and you’ll see common traits - but, if you look closely enough you’ll notice little things that repeat themselves. In fact, all pitchers will in latter innings, depend more and more on these little things, or traits if you will, to see them though. So you might be looking at a higher kick by the back leg - or lower, a quicker knee lift or slower, so on and so forth.
By the way, your question is a darn good one, if you plan to be a pitching coach some day. I say this because when a pitcher is going through a period of difficultly, a pitching coach will watch hours and hours of a man’s appearances and pick out the things that change, even in the slightest. Sprains and strains, endurance deficiencies, lack of stamina, and the like are all signs worth looking for. Also, a change in form and routine - even in the slightest can be signs that a pitcher is trying very hard to reinvent himself.
I know my comments went way beyond your basic question, but your question was a good one for other things.
