I agree with Tricia.

I have made numerous presentations to varying audiences over the past two decades.
The rules I swear by are:

1) Don't give the answer away until the last slide on the topic - keep your audience curious

2) Invite a SMALL amount of audience participation

3) Audiences LOVE stories - share a personal learning experience or something humorous to make a point. Use puns but no jokes. Take care not to put down any person or class of person or where somebody may originate from.

4) Show each slide a MINIMUM of one minute - give the audience time to read everything, study diagrams and take in what is visually displayed

5) Show each slide for a MAXIMUM of five minutes - after that people start getting bored (and your 20 or 50 minutes are running out!)

6) Always illustrate a point with a simple example (use SAS code where it will help)

7) Follow the order Begin, Introduce, Explain and Reveal, Summarize, End. in short:

"Tell 'em what you're gonna tell 'em"
"Tell 'em"
"Tell 'em what you've told 'em"

>Tim