In professional driver training, they allow the left hand in any position from 8:00 to 10:00 and the right hand in any position from 14:00 to 16:00 for the right hand, but you must hold the wheel symmetrically. If you hold the wheel with your left at 10:00, the right hand must be positioned at 14:00. When turning the wheel, I always use the hand-to-hand method, and never use the hand-over-hand method, because it is much safer. When parallel-parking into a tight parking spot I steer one-handed, which is easier with my body twisted backward. When backing into a large spot, I steer with both hands and use just my mirrors without turning to see.