Get close to your audience. Remove barriers, get off stages, walk up the aisle. Wander the classroom, stand at the side, sit in the middle. Leave the podium, put aside PowerPoint, jettison your 3 by 5 cards. The closer you can get, the more you amplify the emotional connection of your message. Get close.
Bonus 1: more pres tips here.
Bouns 2: love presenting, hate (badly used) PowerPoint the book here.