One of the keys parts of the set-up is the posture. Your posture can dictate your swing plane, body rotation and aiming. These are all key parts of the golf swing.
A useful drill you can use is shown below in the picture.
1. Stand straight with arms extended with the club just above waist height.
2. From here start to bend forward from the hips until the club is a few inches above the ground.
3. Then flex your knees so the clubhead rests on the ground, you should feel relaxed and your arms should point straight down from your shoulders just inside your chin.