laugh, think, react.
the most important parts of your presentation are the first and last 60 seconds. think long and hard how you will start "your show". in the first few seconds, your audience will decide to pay attention to you or not. after all, everyone in the audience gathered physically in one room, but their thoughts are not there yet. get their attention.
i typically start with a joke, a short story. or i surprise them. i take off my shoes, saying "i can not think with my shoes on".
one recent presentation, i started with saying "hi. i have only one thing to tell you. one word." and i showed a 