Including the audience in your presentation
Did you ever sit mindlessly through a classroom lecture, daydreaming and doodling on your notebook as a professor droned on and on? Being talked at is an alienating, boredom-inducing experience that is unlikely to produce understanding or action. Even the most well-planned and well-prepared content can become a monotonous stream of indistinguishable sounds if care isn't taken to include and interact with the audience.
Don't be that professor! Build audience interaction into your presentation to keep people engaged and on track.