Empathy and Humor
When speaking with people I generally seek to communicate with empathy and humor.
Trying as hard as I can to understand where they're coming from makes me an active listener. Adding gentle touches of humor or, at least, making sure to laugh signals to the people I'm talking to that this is not serious, we're relaxed. I don't think we stop learning through play just because we're "grown up".
When teaching or mentoring adults, my goal is to enforce a particular relationship: not one of a superior teacher instructing an inferior student, but of two equals exploring a common passion.