I think Dr. Schlect nailed it in this video. If I could add anything: I think that a deep knowledge of the subject area content is also important. As has been said by Hippocrates, Art is long, and life is short - content skill and knowledge is a lifelong quest and the best teachers are the best students. A passion for the subject feeds into the relationships that are being built through sympathy and fellowship.
Thanks for the inspiring video, I am going to share with my Head Teachers!