Silently.
And with actions.
Why do people ask my Teacher, Venerable Master Chin Kung, about Buddhism? Other than the fact from his appearance that he is a monk, it is primarily his demeanor and actions. Over sixty years of learning Buddhism radiate from from him. He looks happy—he looks calm—he looks thoughtful, interested, caring as is appropriate for the circumstances. Clearly, this is a person who knows something.
This is how we teach others about Buddhism. First we practice the teachings. I can't teach someone to drive a car if I'm not myself a skilled driver. Attempting to teach someone without a good level of competency myself, I run the risk of telling them something that is only part of what they need to know or that is simply wrong. Thus, they run the risk of harming themselves or others, and I have committed the offense of harming another
So first we learn.
And we do.
Well.
And with humility.
If people have the right conditions they will ask us because something about us motivates them to do so. We then introduce the teachings as simply as we can. Not because they won’t understand the teachings on a more elevated level, but rather because we may very well not understand on a more elevated level. We do not want to run the risk of inadvertently saying something wrong. And so we stick with the basics, with what we have learned from those who are farther along the path than we are.