Just before your presentation, if you haven’t already, meet and shake hands with your audience members. Ask outright, "What are the issues you grapple with that you want this talk to address?" Presumably you’ve already asked that question of the meeting planner in your Pre-event Questionnaire, but do it again with the rank and file. Then delve into their answer. Doing this with as many people as possible is irresistibly effective - the way we humans are wired, they're going to pay attention to you for the simple reason that you started the relationship by first paying attention to them. It’s like people smiling back at you after you first smile at them. Works every time - get it?! If nothing else, it’s a way of countering the fear of the audience because you’ve met some of them already. Conclusion: they probably don’t bite!