A drive in the country
The truck is an old Mazda pickup with a 5-speed transmission, and no power steering. Over the past 13 years, it has proven to be pretty durable. That, and its combination of low power, easy-to-find gears, and low value made it a good vehicle for a student driver.
Since we started out sitting still with him in the driver's seat, the first lesson was "how to get going". He did very well, launching it the first time without killing the engine, or spinning the tires, on gravel. That's better than I did when I was a kid!
As soon as we got going, I showed him how to bring the truck to a stop, which he also did perfectly.
Periodically, just to make sure he was paying attention, I would yell "Stop!". I had told him that he always needs to be ready to stop quickly, and that I would be quizzing him occasionally. There were a couple of times when he forgot to push in the clutch when he stopped, and killed the engine. But for the most part, he did great.
One of the best parts of this exercise was sitting in the passenger seat with my son at the wheel. He's craning his neck to see out the windshield and saying "This is awesome" every few minutes. We never got out of third gear, and I think we hit 25mph once. But to look at his face, you'd think we were burning up the road.
He said "Today, I'm not going over 20. That's plenty."
Overall, we covered probably 15 miles, saw some cool places out in the country, stopped and threw rocks into a creek and harrassed a snapping turtle, and did some power slides around some curves (I was driving).
It was just a simple drive in the country, but I bet I remember today for a long time.