There was a period in my life when I would say no, and I didn't know why I was saying no. In most cases, it was out of fear, just trying to be safe. Because 'no' will keep you safe. 'No' won't draw attention to you. But all the cool things are on the other side of 'Yes, And.'
There are a million ways of arriving at a performance, any number of them solid.
Teaching someone to be funny is like teaching someone to be fast. They're already fast. You're just making them faster.
The lifelong goal of an improviser is to listen to what the other person is saying, taking it in, and responding.
Baseball players practice, runners practice, so how can you practice being funny? You get up onstage. You train as an improviser, playing make-believe, using the vernacular of improvisation, saying 'yes and' to other people's ideas, making statements.