ive had many good coaches over the years. some understand mechanics better, some have a better idea of verbal cues that tend to be effective. ive been coaching young pitchers for a few years now.
House, Thurston, etc, these guys are all good, all have something to offer.
for me, the guy who ive seen make the most effective presentation of the mechanics of pitching is Brent Strom. because he gives good ways of making young pitchers understand, in simple terms, what they need to do to throw hardest. and what they should feel physically.
coaching is part art, part science. each kid is different, and learns differently. ive found it very interesting to see how some kids make adjustments after verbal cues, where other kids need to really feel the movement before theyre able to make the change.
for that reason, i think its important to keep in mind theres not one perfect approach or method to follow every time. each case is different. what works in one case might not be as effective in another.
when you find what works for a kid, though, thats the exciting part. thats when u get to really see the improvement and feel like you had a part in it. so my advice is to keep experimenting, keep researching to get new ideas, keep an open mind, and you'll find you can make a difference in a young pitchers progress.
anyway, thats my input. hope my response wasnt too far off topic.