Remember that the audience behaves like light. It is made up of individuals (photons or particles) that you can address and stimulate in isolation. But the audience also behaves like a wave which can be directed and redirected. Remember that you are not speaking to an audience, you are speaking to everyone in the audience. So don’t just look at “the audience”, see individual members of the audience. You see particles and you feel waves.
If the audience is sluggish, distracted, or seems unsure, engage with individuals, energize one and then another rolling them together into a seamless wave. If the audience already seems to be an overwhelming wave, isolate one individual and then another, calming them down, and the wave will begin to break apart and settle.
You have to love the fact that the audience has come, is sitting, and is listening to what you have to say. They are giving up time in their lives to listen to YOU. Let them feel that love. Show them you love your work. You love what you have to say. And you love the opportunity to share this with them.
Recognize and acknowledge the audience for who they are. Respect what they know, who they know, and their cultural expectations. Listen to them, respond to them, and compliment them: be prepared say “that is a good question. Thank you for that question.”
Try to see and reach every member of the audience. Impress upon them the simple message you have to deliver. It is an important message that you are entrusting them, your audience, to deliver to others.