As a coach I see all sorts of strange bow hand positions. It is important to get your hand positioned properly. It is your only contact with the bow. Too much hand on the bow and you have a better chance to torque the bow. An improperly positioned hand leads to other improper arm and body positions.
Stand with your hands relaxed at your side. Note the natural position. Now raise your hand keeping that same natural position. The web of the hand between the thumb and index finger should form sort of a ‘U’. Next, point the natural ‘U’ shaped hand position at the middle of the target. Insert bow and lower your life line to the middle of the grip. Maintain the relaxed hand and finger position through the shot. You WILL need a finger, or wrist sling. Here are a couple of pictures to help.
Please note that the open hand pointing to the target is a step in the process of attaining a proper grip, not a final position. When the life-line is positioned on the middle of the grip, your knuckles should form an approximate 45 degree angle, as pictured.