Mary Karr writes memoirs. She also teaches writing. In this piece from the current New Yorker she talks about what makes writing come alive. 

Carnality sits at the root of the show-don’t-tell edict that every writing teacher harps on all the time, because it works. By carnal, I mean, Can you apprehend it through the five senses? In writing a scene, you must help the reader employ smell and taste and touch as well as image and noise. The more carnal a writer’s nature, the better she’ll be at this, and there are subcategories according to the senses. A great glutton can evoke the salty bite of pastrami on black rye; the sex addict will excel at smooth flesh; the one with a painterly eye visual beauty, etc. Every memoir should brim over with the physical experiences that once streamed in—the smell of garlicky gumbo, your hand in an animal’s fur, the ocean’s phosphor lighting up bodies underwater all acid green. Of all memoir’s five elements, carnality is the most primary and necessary and—luckily for me as a teacher—the most easy to master.

You may not realize it, but this advice applies to presentations as well. Not real carnality, but helping the audience experience what you want them to understand. Don't just talk about something. Whenever you see yourself writing words, ask yourself whether you can show with examples what you are about to talk about. In the world of show-and-tell, show trumps tell.