Make sure your teen has a learner's permit, license or any other requirement necessary before beginning driver training.
Review the rules of the road the teenager learned during the required classroom hours.
Drive to an empty parking lot or driving course.
Explain the basic workings of the entire car, inside and out, before letting your teen start the engine. Go over each part and process in detail, including everything under the hood, the dashboard controls, the gas tank, the tires and the emergency equipment. Repeat until you're sure your teenager understands.
Demonstrate how everything works: the lights, seat belts, windshield wipers, blinkers, horn, emergency lights, transmission, seat adjustment, steering wheel, mirrors and defroster.
Sit in the passenger seat and have your teen start the engine.
Point out how acceleration, braking and smooth transmission shifts feel.
Give corrections, warnings and tips as you make your way around the course, and discuss overall points when you've finished.
Sprinkle your lesson with what-if scenarios. Cover such possibilities as a child running across the road, traffic signals going out, emergency vehicles pulling up behind, a tire going flat, and so forth.
Remind your teen that it's important to always have the car's registration and insurance information accessible in the car and to carry a driver's license or permit.
Note skill improvements and make the course progressively more difficult, finally going out into traffic when you think your teen is ready.
Practice again and again.