As a presenter you must be deliberate in everything you do, say and show in order to micromanage the attention of your audience. If you don't the audience will likely focus on the wrong things: what you were saying two minutes ago (but not what you're saying now), minor details vs. your main point, that laser pointer you're swinging around like a light saber, or daydreams of their upcoming vacation.
So avoid dropping a presentation bomb I like to call a 'weapon of mass distraction.'
Here are five big bombs to avoid:
Ice breakers. You know, things like golf jokes or instructions to hug the guy next to you to kick off your presentation. If you're trying to create some interest in a way that doesn't provide perspective on your topic, you've already got them distracted. And you haven't even started on YOUR message yet.
Bullet points on your slide. Yes, you read that right. The audience can't listen to you and read bullets at the same time. Pick one. I prefer you say it instead of showing what amounts to your speaker notes.
Too much content on your slide. If it is important enough to include in your presentation, it deserves to have its own slide. For example, if you currently have three charts on one slide and they all are important, break them into three slides so you and your audience can devote all your attention to each one at a time.
Personal delivery tics. Those weird little behaviors most of us exhibit when in front of an audience. The most distracting tics are the things that are repetitive: Filler words (like the dreaded 'ums'). Pacing around the room or doing the 'Chained Elephant' (one step forward, one step back, repeat until end of presentation). Repetitive hand motions (like 'knife hands'). Hands in pockets for a really long time ('what the heck is he hiding in there?').
Inauthentic or incongruous delivery. Your body language, your speech pattern and your content need to be aligned. If you say "I'm really excited about this product" but your voice is soft and monotone, you have a frown on your face and you don't make eye contact... will your audience believe what you're saying or how you're saying it?
There are more but if you can knock these out you will be on your way to drastically improving your delivery.