I think, first of all, you need to love what you're doing, and then this helps in the comedian for its part in everything-but the moment you enjoy what you're doing, you try to express yourself, to find your way, and every time is different, of course.
Some people are like wheelbarrows; useful only when pushed, and very easily upset. The time to stop talking is when the other person nods his head affirmatively but says nothing.

