I have three rules when I speak.
(And the first is the most important...)
Do. Not. Bore.
The content of Shakespeare and the face of George Clooney can't salvage a lifeless, boring talk.
At the heart of every memorable presentation is some level of entertainment and emotional engagement. That's why my talks are always rooted in good storytelling. And good storytelling opens the door for the content to make an impact.
Here's a test for your next speaker: Ask one of the listeners to recap their talk a week later. It's likely they won't be able to recall much (if any) of what they learned. This is what happens when mediocre presenters cobble together random anecdotes for 30 minutes. I infuse my talks with memorability so the listener is able to process and implement the content long after the talk is over.
distract the A/V team
In a conference setting, the toughest crowd to engage are the folks running the sound and lights. Why? Because they're the only people in the room not actually there for the content.
My goal is for the talk to be so good that they look up.
That's why I love watching them when I speak. Their attention is the hardest to capture (which is why I want it). I know that if I win the A/V crew, I win the room.