Re: Left Hook- palms down or facing inward?
Depends what you are trying to achieve with the punch and what openings are present at the time.
It amazes me how many people ask how to throw this punch, that punch and the other punch. If you only had one style of jab, one way of throwing the right hand, one type of hook and one way of throwing the uppercut, you would be an extremely limited fighter. A good fighter needs to be versatile to be able to adapt to different situations.
Practice throwing all shots, from all angles, with differing angles of the hand at impact, from all ranges, off the back foot, off the front foot etc.
If I have said this once, I have said it a million times - the more options you have, the more problems your opponent will have.