I've always told my kids, imagine you have a 2 digit number on your jersey (like #17), try to show the pitcher the #1 of the #17 when you begin your movements. But do it using your back hip in concert with your back shoulder. Some of the hitting guru's might say this is all wrong, and why my kids hit line drives instead of home run bombs. (It could also be in part because they are both 5'-04" and 115 lbs dripping wet!)