Take a look at this top technique:
As you step up to talk, your audience might be having quite a few different conversations going on inside their own heads. Far from being the immediately attentive audience you want, they might be distracted by work issues or something going on at home.
Distracting them with something out of the ordinary is a great way of getting their attention and raising their curiosity about what is coming next. This is a short, but important video!