I seem to have an issue. When I step forward with lead leg my leg (in order to be at lead shoulder width apart) also steps slightly to the side and my head follows which,to me, moves my head off original shot line. Another issue is I bring my cue/bridge hand in from the left and as I’m bringing it in my body/head twists with it
The lower body will need to assume a multitude of configurations depending on the table’s relationship to the shot.
The ideal stance provides the player with the upper body alignment characteristics it should try to emulate, regardless of how the lower body needs to morph.
It serves as a reference.
To that end, I lead into the shot with my head moving down the ball path.
I start with both hands on the cue opposite my dominant side.
Rather than sweep onto the shot plane from either side, I start a forward slide of the cue in the bridge towards the target path chosen before the approach.
The grip hand draws back slightly matching the cue line to the direction of forward slide.
The upper body needs to fold onto the shot aligning the dominant side, to be able to deliver the cue in a straight line.
I find that whenever possible, I use the hip plane to do the fold.
Bend from the hips not the waist when possible.
The passive grip hand needs to be able to remain passive during proper alignment.
Once you think you are aligned preliminary strokes should confirm or deny the straight stroke of an elbow hinge.
The hand is not the adjustment tool.
Get your body and the dominant side fold right, by starting over.
Make sure the fold clears the dominant side hip by rotating the hip plane towards the cue ball.
The rear leg usually straightens as the hip rotates away from the shot line clearing room for the cue and grip hand.
This is a singular description.
Any repeatable configuration of the upper body that consistently aligns the cue and allows a straight delivery by simple hinging of the cueing arm and elbow, will work.
Find that slot and how to get there repeatedly.
Let the upper body lead, starting with the head.
Get everything moving towards the target area, that needs to align on your dominant side.
The lower body must allow you to be able to get still and deliver the cue while maintaining your balance.
Try a one handed stance to see how many of the boxes it checks.
Fix any flaws then learn to fold the bridge down the target path.