As I am not really a professional in this field of study, I’ve only understood some concepts of humor.
Jokes have millions of forms, and millions of stories. A nicely delivered joke has multiple factors to actually trigger the laugh from audience.
Twist, unexpectedness, incongruence, and many other elements constitute a good laugh for audience.
However, to actually understand humor, or jokes, is actually pretty hard. As not everyone would get the joke and not everyone would laugh on a joke. People have different tastes.
Usually, the humor we see on televisions are mostly twists. Twists make everything out of expectations. Audience thus laugh on the incongruence between the result and the story.
Surprising the audience is the way to go for a smile or a laugh.
Some people do it by delicately designing their jokes and incorporating them into the stories they’re telling. Some people do it by improvisation, the sudden movements of body, or the sudden change in tone or expression.