Doesn't really matter what sport, follow through improves the accuracy. Tennis, golf, baseball, all have the mantra of follow through.
Shooting a moving target, like in clay sports, lifting your head before the follow through is probably the hardest habit to break with a student. Also makes it impossible to hit any doubles.
Shooting a still target board, it not only ruins your shot, but it makes it harder to hit the follow up shot too. Lifting your head off the gun too soon will quickly get worse and become a flinch.