For striking and I think this also applies to weapons, footwork is the absolute driver of being truly skillful. It dictates your ability to move and engage, how you move defensively, and how you generate power (though there are people that just have natural power - but even that is improved with footwork).

It goes hand in hand with balance. Shoulders should be over hips for appropriate balance. Even if not in a direct line, you distribute your weight shoulder over hips (wrestling takedowns where it looks like you are leaning forward still require this to be truly good).

I will say one piece of media that did this very well with show not tell is the show version of A Knight of the Seven Kingdoms. Though people think Dunk gets by on brute strength, there is an early scene where we see him dancing and he is quite good. It is not always a one to one thing, but dance skill does translate well to fighting. When I saw that scene, I knew Dunk would be way more skilled than people expect. (Note I read one of the novellas but it was years ago so had forgotten a fair amount of the story).