This is going to require a video, but ponder this.
The backswing from the waist up consists of three movements that need to be cohesive.
1. The wrists hinge up
2. The arms rotate so the hands rotate 90*
3. The shoulders turn at 90* to the spine.
You do these things, you end up with what most would consider an excellent backswing.
If you do it correctly and individually in the order I listed, you will see a beautiful thing.
The hard part is doing them cohesively and that’s why we all stink.