Two images that will help... a very common issue, one that I fight too at times.
First, when you setup to the ball imagine a line through the ball that is perpendicular to the target line and stay behind that line as you look at the target/step into the shot, making the last part of the routine to step over the line with the left foot (this is an image from Ben Doyle's routine). Setting the clubface while you are standing behind the line helps keep you from aiming right, then you can use the clubface as the guide to match your shoulders.
Second - as you look at the target before the shot, let your head pivot on your neck and 'look through a window' at the target - an image from the late Davis Love Jr. A lot of times people will lift up out of posture/turn the shoulders to look at the target, which just gets you out of alignment.
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Try this. 1.Starting from behind the ball and in line with where approximately you want your feet to be at address 2. Walk forward keeping your eyes on the target or an intermediate target 3. While looking at the target set your feet 4. Without taking your eyes off the target allow your body to settle in 5. Now look at the ball and adjust for ball position and reach without changing your alignment.
This works amazingly well provided you do not look at the ball in the process, until you are settled (trust me you will not walk past the ball). I have had countless students do this and they are spot on to where they need to be.
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