You've heard about being authentic and maybe you've even read Lencioni's latest book Getting Naked.
So you go on stage and do one of the following:
1. Tell your audience you aren't good with presentation tools. (And do it right before you start showing your PowerPoint slides.)
Say things like "I'm not good with PowerPoint".
"I don't know how to advance these slides."
"I am not used to working with this computer."
This might feel authentic (especially if it's true) but you have just killed your credibility. If you don't know how to use the tool, then do something else - speak without slides or use a flip chart. If I am sittiing in the audience at this point I will assume that you didn't care enough about your presentation or me as a listener to get help with the tools. Use a tool that you know or do without.
2. Speak on something other than what is listed in the agenda.
This is a classic case of not delivering what is promised.
Sometimes the presenter has no control over a topic change. Maybe he is brought in as a substitute speaker and is given a new topic. I just attended a conference where this happened and all of the questions following the presentation were related to the original subject - can you answer questions on this topic? If you are the presenter, make sure that conference materials are updated to reflect your topic.
3. Go over your allotted time.
Or worse, start out your presentation by asking how long you have to talk.
Your audience will know how much time you have been allotted and will be annoyed that you haven't taken the time to be prepared up front. If you talk over your time and are sharing the agenda with others, you will appear inconsiderate and unprepared. And you run the risk of taking away from other sessions that follow you. Know how much time you have and stick to it. Assign a time keeper in the audience to give you a five minute warning.
4. Tell the audience they know more than you do on your chosen subject.
Again, kudos for trying to be humble, but if I am in the audience, I will immediately begin to wonder why you are onstage if you don't know more than me. If I have paid to hear you speak I will be even more upset and will be unlikely to pay attention to anything that comes after this statement. Find other ways to show your humility - you might not be the expert on all aspects of this subject, but I bet there are areas where you have far deeper knowledge than anyone else in the room - work from that perspective.
5. Use a confusing theme that doesn't connect to your topic.
I love a good theme or analogy. Used properly, it can make complex information understandable. But done poorly, a theme can take away from your message. I have seen themes that are so obtuse they have no apparent connection to the topic at hand. That makes me want to solve the puzzle. I will obsess over the missing connection until I hear nothing the speaker has to say. The same thing happens with overly detailed graphics. You flash a picture on the screen and I can't tell if it is a rabbit or a person's arm and I spend the rest of the time trying to figure it out. Rather than adding to your message, the image detracts from it. Your point never reaches my ears. Connect your theme to your point and use clear graphics.
There is a fine line between being authentic and losing credibility as a speaker. If you don't know the difference, get someone to help you before your next presentation.