Many problems in young pitchers stem from the posture of the upper body at release. Some people don't bend at the waist before release, which results many times in a high throw or inconsistent location. A lot of pitchers will end up in a bent position due to cues from coaches to make sure and follow through, but sometimes the release happens to early in a standing position followed by the bend.
Outstanding observation... and one of the major reasons for sore elbows, sore necks and a lot of base-on-balls.
This upper body discipline does not come about over night. It takes deliberate practice .. sometimes in front of a mirror to ACTUALLY see the desired results and FEEL said same. This upper body posture also supports the Drive forward when you pitch OFF YOUR STRIDE LEG and when that stride foot plants deliberately.