I would suggest you concentrate on taking the club back straight (not to the inside) and keep it low for at least the first two feet of the back swing. A good way to achieve that is to push the club back with the left elbow. Make sure you make a full shoulder turn and, if possible, have someone look at you to make sure you don't lift your head. From there you may be able to forget everything and just let it happen. The downswing starts with the lower body but if you get into a good position at the top that is almost natural. Keep you head behind the ball!