Audience members are not always friendly. Unfriendliness comes in 2 types:
  1. the civilised audience who is reluctant to agree with your proposal (I faced many of those as a management consultant) and  
  2. the heckler who is out there to interrupt and derail your presentation (probably on his own).
Audience 1. A fatal mistake with audiences that do not agree with you is to invite the full debate before you have had a chance to tell your story. Highlight all the points and data quickly before you get to some slide that presents the trade off your making. That trade off slide is very important. Many of these strategy debates go in circles and keep on repeating the same points. If you have written down the point on the slide you can point at it and say “You are right, I have captured that here.”. Group/isolate/give less space to the points everyone agrees to and focus on trading off the difficult ones.

Audience 2. Hecklers are difficult. The best strategy is to try to get the audience on your side. If you ask - after 3 detailed questions - whether the audience agrees that these points are better discussed one-on-one after the presentation, there is a good chance that the heckler will stay quiet.  In addition, after you answered the heckler’s question, turn away from her, and make eye contact with another person with a question.