The most common alignment error that I see is the mismatch between the club face and forearms/upper torso. When the upper body and forearms are aligned to the left of the target but the club face points at the target, the club face is effectively open. When you combine this with the average golfer’s tendency to under rotate their body at impact, you get a perfect storm of misalignment that frequently leads to a slice or the overcompensation of a big hook. This setup error is often compounded by a lack of spine tilt away from the target.