When establishing your setup, it is important to have good posture and feel balanced. From this position, you should maintain your spine angle throughout your full swing. Many amateur golfers have a tendency to raise up during the downswing in an effort to lift the ball up. This can cause a variety of poor shots, including a topped shot. By maintaining the spine angle, you can hit down on the ball properly. Good posture, balance and body rotation are critical to maintaining your spine angle.
Grip the club and take a shoulder-width stance. Flex your knees slightly, bend forward at your hips and push your rear end back. Keep your back flat and tension-free. Do not round your shoulders. This gives you the proper spine angle at setup. Distribute your weight equally on both feet. The weight should be on the balls of your feet -- not the toes or heels.
Swing the club back with your shoulders and allow your hips to rotate. Rotate your left shoulder (for right-handed golfers) down under your chin as you swing the club back. Maintain the flex in both knees as you swing the club back. Stop your backswing when your left shoulder is under your chin. Both knees should still be flexed and your weight should still be on the balls of your feet.
Turn your hips toward the target to start your downswing. Let your right shoulder rotate down under your chin as you reach impact. Keep turning your hips toward the target as your right shoulder swings under your chin. Your left leg will begin to straighten as you swing through impact.
Turn your hips and shoulders through so they face the target. Your right shoulder should be tilted slightly lower than the left at your finish.