The form brings you relaxation. Relaxation is a process and a goal. One cannot simply just "relax." It does not work that way.
Sense the tension in your body. Correct the form to relax the tension. Use as little muscle as possible.
The only part that needs to be strengthened is the core from the pelvis to the ribcage. The legs, arms, shoulders, and head are as relaxed as possible. They just need enough tension to be in position. Lengthening the back of the head a little will stabilize the spine and head.

"Needle in Cotton." Imagine your body, especially the trunk, as a needle. The needle leans and swings side by side. Regardless of direction, it is ONE part moving. The legs and arms swing as a product of "needle moving" to counterbalance. Meaning that I do not have to swing my arms actively. Just let it happen.

To prevent energy leaks, the arms and legs should be as close to the trunk as possible. Drop the shoulders and have the arms rest on the lats. This is the most relaxed and powerful arm position.

The hardest part and most mistake I made when leaning is "over lean." It is because the proposition sensing is not good. Practice the sense of lean, a subtle lean, a subtle angle. And practice to let it go.

Why? When not feeling enough lean, I pushed hard on the ground. When feeling overlean, I put on a brake. None of them is optimal.

Peel my heels up the ground. Do not pick up my knees. This is the mistake that leads to muscle cramp very quickly.

Practice Lean, Body Sensing.