The only other things I can think of you could teach him is
-"Know your target and what lies beyond it"
- TAP, RACK, BANG
- B.R.A.S.S. (Breathe Relax Aim Sight Squeeze)
Acronyms and little sayings are a great way to help new shooters remember what to do. In the Corps we called it a "diddy" and it worked for even the dumbest Marine you could find (which I've met some doozies). You sound like you did a great job already though. Keep it up .