Skilled presenters know that if they step back and listen, their audience will take a step towards them. Often, the speaker will begin by asking a series of questions that are impossible to say no to. After the audience has answered yes a couple of times, it gets easier to say yes to other issues the speaker wants them to agree on. Another way to state your message is with a story or humor. A story offers a mental picture, which a listener will retain long after the facts and figures are forgotten.
Anecdotes work in the same way.
Humor is a bit touchier, because in the hands of the wrong person it can be disastrous. Even the most skilled speakers would not put themselves in that position. Involve the audience. On the other hand, a speaker who knows his subject is comfortable and has a natural style of delivery. Capitalize on moments of opportunity by using your voice properly and precisely.