Ask yourself, first of all, why listeners will be attending. Is their attendance mandatory, as are some training sessions or division-wide meetings? If so, be aware that you may have to fight to gain and keep their attention. Even if the topic and messages are something they should be interested in, compulsory attendance may blunt their enthusiasm. Plan ways to engage the indifferent listeners—perhaps by adopting a lighter tone, using humor in your stories and examples, or surprising them with the novelty of your approach. Such tactics will enrich the experience for them (as well as for those who come in interested and eager to hear).
In other presentations, audience members will be there of their volition, attending because they want to hear what you have to say. That's good to know, too, because their initial interest forms a common ground on which you can build. You still need to sustain it, of course, through clear messaging, relevant and strong support, and aligning your purpose with that of listeners.
For either motive, and all that fall between, remind yourself as you prepare and rehearse of the question all audience members have: What's in it for me? The speaker who attends to the WIIFM question remains aware that audience members are looking to connect to messages, and the surest way to form and maintain that connection is by illustrating how those messages affect them.
In some organizations, presentations provide a playing field where reputations are burnished or tarnished in front of the assembled hierarchy. This means that some audience members may hang on your every word to use it as a launching pad for an attack designed for some political or strategic ambition. Thinking this through so you provide a springboard for your supporters while denying footholds to detractors is an essential survival skill associated with assessing audience motivation.