Weight shift. That’s it.
If your weight is shifting to the front side to initiate the downswing and your upper body didn’t move forward too…you are properly tilting behind the ball and giving your arms room to swing.
That is why that hip bump at address is so helpful. It gives you the feel of where to return the weight. Almost presetting a weight shift in the setup.
What the right knee is feeling is a key. If you feel your weight pressuring your right knee to buckle, you probably have some hang back.
If you feel your rotation naturally causing some relaxed right knee bend, you are probably shifting.
This is a very fine point in the swing, as hanging back on the back side is problematic, but so is not having any impact tilt by getting in front of the ball.
This falls into the same category as swinging from the inside. You want to come from the inside, but if you do it too much, you will be stuck under the plane and forced to flip.
To use the word “key” again, the key is trying to allow natural things to happen, instead of forcing the opposite of “bad” to happen.
People who don’t want to hang back move their entire upper body in front of the ball. People not wanting to come over the top, get trapped too far inside.
These issues come from forcing the opposite of “bad” to happen. What you want to do is to gradually move yourself into a natural motion, by figuring out why the poor movement is happening and make an effort to avoid it.
The slow improvement of just being aware and making an effort to do it correctly for you, is how you get better with any swing issue.
The “key” is to find a personal feel that gets you moving in the right direction.