A lot is made of the body motion in the swing but how you use your club, arm and wrist structure is fundamental to creating power and controlling the club face. Golfers have their own individual mix of how they pull and twist the handle and unwind the shaft but at the core of all of this is the basic understanding and attainment of the classic 'L' shapes.
This is a key concept of the swing that will enable a fluid and efficient movement that delivers an impactful square contact with the ball.
The essence of a good golf swing is to 'Move Like and Athlete from One Spot'. It's the second part of that description that will enable you to put a consistent strike on the ball and maintain control of the club face. Everything we do has to revolve around a centred and balanced body position.
Maintaining your width of arc will help to keep you in sync and greatly increase your consistency.