Any mark placed by the player or with his knowledge to indicate the line must be removed before the stroke is made.
Still, this can be useful. Set a club down and align it to the target. Then take your stance, and look down the fairway to see where where your feet, shoulders and eyes align. After you remove the alignment tool, be sure your align your body to the previously discovered line. Try this a few times in practice rounds, and your alignment is sure to improve.
This mental golf tip is an excerpt from The Five Inch Course: Thinking Your Way To Better Golf.