You know the easiest way to improve your golf swing? I do, I’ve been swinging golf clubs most of my life, that is very simple.
The most “awesome” drill in golf (Swing) is to swing your golf club with just your left hand (or your right hand for lefties), then try to feel very powerful.
Just try to swing with one hand and see if you can swing really fast but under control. This pretty much is your golf swing, your left shoulder.
Next time you swing a golf club, just make a simple practice swing imagining your left shoulder controls everything.
What I do is a rehearsal swing with just my left hand and shoulder then go really fast with one hand. Once I can do that two hands become a piece of cake.