Try to schedule driving practice at a time when nobody’s stressed about something else, upset, or tired. The night before you are giving a big presentation at work or he is having an algebra midterm are not good choices, especially not at first.
In keeping with that, keep any conversation to positive or neutral topics. Driving practice isn’t the time to discuss his lousy grades or the fact that you think his girlfriend is a loser. No yelling or screaming, unless he is within seconds of hitting something. If he’s yelling or screaming, he’s probably had enough driving for now.
No touching the wheel or grabbing at him, unless he is literally about to hit something.
Try to find a time to practice when neither of you is too tired, and especially when he’s not too tired. That time is going to be different for everybody. If he’s not a morning person, for example, don’t schedule your practices for weekend mornings. If he’s yawning or looking tired while driving, it’s time for that practice session to end. Driving when you’re tired is dangerous even for an experienced driver.
If he’s clearly getting frustrated, or you’re losing your patience, it’s time for that practice session to end. Being upset or angry doesn’t improve anybody’s driving.
I would recommend lots of short practice sessions rather than a few marathon ones if at all possible, just because of the possible fatigue and frustration issues. Another advantage of lots of short sessions is that it can give him more practice with different weather and traffic conditions.
Tell him what he’s doing right and wrong, and be as specific as possible. One of the worst parts of learning to drive for me would be when my dad would say “Gently, gently”, and I had absolutely no idea how to modify my driving to go along with that. It would have been much more productive and less frustrating if he’d said specific stuff like “don’t brake so hard” or “slow down”.
I would start with a “no music” rule, but eventually allow music once he gets a little more experience. I’d probably allow CDs/Ipods with a no-messing-with-the-console rule first, then unrestricted CDs/Ipods and radio.
Some other rules that I’d start off with but might relax or get rid of eventually:
No one except you (or a driving instructor) and him in the car, if at all possible. No friends, younger siblings, etc.
Cell phones, both yours and his, must be turned off while driving.
No touching the driver, especially if he’s nervous like me.
No food or drinks while driving.