Heel shots are caused because you either move the center of your plane out towards the ball during your swing or you start too close to the ball at address
If you tend to come up out of your stance and hit thin shots you can not only fix that but also increase your clubhead speed with this easy drill using a block of wood to place your toes on
There are two parts to the release, one is the arms turning over and the other is the body turning, we need both of these to release correctly but most of us tend to over emphasize one of them