Re: The optimal foot/ hip rotation, how do the pros do it? Hows it done?
Yup, endless practice combined with watching an imitating the greats and picking out what you see and mixing it with what feel natural for your own style.
Practice throwing shots and combinations in front of a mirror, preferably a full mirror so you can watch every minute detail in your own execution. Tommy Hearns was obsessive about rehearsing his shots in such a fashion and it was one of the critical parts of training in the 1950s. It seems to have fallen out of practice lately.
I used it to hone my form. Granted I've never fought amatuer even but used to spar quite a bit and it was amazing how much I picked out and fixed in my game by throwing punches at a mirror.