It’s easy to rotate your body side to side when standing upright. However, doing it while bent over – as golf requires – gives some people trouble.
If you have a tendency to raise up during the swing, you likely hit a lot of thin shots and the occasional top. It’s crucial that you learn to maintain the same spine angle from address right into your follow-through.
You’ll need a full-length mirror, reflective window or similar surface for this drill:
Do this several times as you focus on keeping the same spine angle from address until after impact. Then try it with your arms extended as though holding a club, still with the goal of a consistent spine angle.