What makes people laugh?

It isn't always that hard to get people to laugh. Try these suggestions:

Pull silly faces, tickle them, Imitate well known things, e.g. Cinderella, babies, animals. Do an impression of well known people. Do a scene from a well known play and add a modern character in it. You could also pretend not to know a very obvious thing. Throw a small counter at the audience and make sure it hits someone. Then pretend to act so sorry as if you are going to fall apart. To make something really funny, you could put a hero from one film and a villan from another together and act out what they might say to each other.

If you just want to stick to the classics, pull silly faces, do weird ways of walking and, if you're a natural, do some ultra mocking impressions.