This is one recommendation, however, that I've never even considered following, even though it has been suggested to me on a number of occasions throughout my career. I've also heard well-meaning teachers and advisors give this advice to students. First off, it sounds incredibly silly. I have enough trouble trying to remember what I should be saying without the extra mental effort that would be required to envision the audience without their clothes on. I could see myself walking onto the stage, turning to face the audience, trying to picture a roomful of naked people, and then blanking out completely on my speech as my head filled with unsavory images of my colleagues in their birthday suits. How would I face them later and carry on a conversation with a straight face?
No, no, no. This is bad advice not only because it's disrespectful of your audience but because it puts a barrier between you and them. Just the opposite of what you should be doing: Connecting with your audience. If you are afraid or contemptuous of your audience, then you are not connecting with them. If you are not connecting, then it's likely they are not paying much attention to what you are saying. Putting up barriers between you and your audience (huddling behind a podium, reading your speech and never looking up, looking at the screen with your back to your audience) makes for a bad presentation. Audience members will understand at a gut level that you are not confident about yourself or your message. People are incredibly skilled at reading body language, even if they are not quite aware of it at an intellectual level.
Along these same lines, I've heard about another "trick" that some speakers use to avoid looking into the audience members' eyes (but appear to be doing so). The trick, apparently, is to look at people's foreheads instead of their eyes. They supposedly cannot tell that you are faking eye contact. I'm not so sure that's true. If you are faking eye contact, you likely are giving off other subtle hints that you are afraid or insincere, which the audience will spot. Avoiding eye contact tells another person that you are not trustworthy and have something to hide. Faking eye contact is also bad advice because it means that you are missing important feedback from your audience. If you are not looking, you don't know if your audience can hear you, can understand you, or is interested in what you are saying. If you see negative expressions, maybe you can't do anything during that speech but it will be valuable information to help you improve your next talk.
Whenever I see someone in the audience frown or shake their head–it is disturbing–but I try not to dwell on it. I continue to look around the room until I see someone nodding or smiling. Another thing to keep in mind is that the audience members could be mirroring your expressions and body language. If you are exhibiting nervous tics or even fear, your audience is going to be uncomfortable and fidgety. If you are relaxed, smiling, and looking straight into your audience's eyes, they will likely feel comfortable and good about themselves and you.
Being nervous is no excuse for failing to make a connection with your audience. In fact, on the few occasions when I've heard a really nervous speaker admit to the audience that they were terrified of speaking, the audience immediately became sympathetic and encouraging. Most people want you to succeed and can empathize with your nervousness. If you have to imagine your audience in any condition, imagine that they admire you and are there to learn something from you.
