Don’t Talk to the Screen. It’s hard to hear what you are saying, it is rude to turn your back on your audience. You can’t make eye contact if you aren’t facing forward.
Don’t Read Graphics Word-for-word to the Audience. Reading to an audience may be perceived as arrogant or patronizing. It also makes it look like you are unprepared; you don’t know the material well enough to look away from it.
Don’t Gawk at Your Visuals. Don’t give the audience the impression you have never seen your graphics before.
Don’t Point Out Mistakes or Poorly Designed Graphics. Small errors may hurt your reputation for being careful and thorough but there is no reason to disparage your own work, thus hurting your credibility. If it’s not important, leave it alone.