People ask me what the hardest thing I do is and the answer is simple; tell a joke. Why? Because once you've delivered the punchline, there is nothing else you can do except hope that the audience will laugh.
The few seconds it takes for an audience to give you their reaction can be the longest of your life. So here's a link from Inc magazine offering up 16 to pick and mix any kind of speech. My favourite? "Few great men would have got past personnel." Paul Goodman