In short, your left hand always stays on the left half of the wheel. Your right hand always stays on the right half of the wheel. So, the highest your hands can go is where both hands are at 12 o'clock (your hands touch their index fingers together). The lowest both hands can go is 6 o'clock (where your hands touch their pinkies together). Your hands never leave contact with the wheel. If the wheel is stationary, both hands are gripping. If the wheel is moving, one hand is gripping (the one that is turning the wheel), and the other hand is sliding, although you should "unwind" the wheel by relaxing both grips.

Some countries won't let you pass your driving test without using this technique of turning the sterring wheel through out the test.