I think to be a great PMM leader, it's really important to have done the work. So to have owned massive product lauches, designed narratives, led sales trainings, etc. PMM can be an ambigous job so a leader that hasn't been there done that usually isn't succesful.
The hard skill then left to learn is management. Coaching, support, leadership, alignment. That's a hard skill that you can't overlook. Just becuase someone is a great PMM doesn't mean they will become a great PMM leader. It takes knowledge, practice, and time to acheive that just like anything else.
I tend to keep my communications short, sweet, and to the point keeping the mentality of "what's in it for them" at the top of my mind. Bullet points and a TL;DR summary help with this. Make sure there is a crisp ask or offering at the end if you are hoping for a next step. And as you would with anybody you work with, be respectful of their time!