Playing with proper hand position is important to avoid injury and to play as effeciently as possible. As a general rule, place your thumb in the center of the back of the neck in line with your second finger. Imagine holding a tennis ball in your left hand with curved fingers. Play on the tips of your fingers and aim to keep a gap between your palm and the side of the neck. Notice the angle of the fingers in the images: the index finger points slightly to the thumb side, the index finger slightly less to the thumb side, and the ring finger and pinky point in the opposite direction.