I once had a presentation to an executive team for both my employer and one of our largest customers. It was to show them the results of a massive product anylysis project where I reviewed hundreds of products they stocked, both from us as a supplier and all other suppliers.
I started my presentation with “Unlike many people, I don’t usually get too nervous when doing public speaking. Today is an exception. (referring to the customer) I don’t know any of you yet I’m about to tell you how to run your business.”
It got the expected laugh, broke the ice and went very well from there.
That’s a good Icebreaker.
Humor, without it being too vague or too vulgar.