Guest Post by Mary Civiello

Most of the executives I work with–at companies such as Morgan Stanley Smith Barney , American Express , DreamWorks Animation , and Siemens AG —are experienced presenters. But even pros who just want to put some polish on the silver may underestimate the opportunity–and the risk–in any given presentation. If you want to shine and avoid the tarnish, consider these four tips to help you be the best you can be at communicating with a crowd.

1. Can you give your presentation in 20 seconds even though you have 20 minutes to speak? Start your preparation by asking: What is the one thing I want them to remember if they remember nothing else? Studies show that by the end of the day, your audience will have forgotten half of what you said. And by the end of the week, 90% is forgotten. To make sure that the 10% that sticks is the 10% that you really want them to remember, say it early and clearly.

2. Do you look and sound like you do in a conversation? Think about your talk in terms of moods, not just information. Ask, “How should I feel when I deliver those three slides vs. the next three?…Am I giving marching orders, or am I sharing an example?” In delivering different parts of your presentation, you should look and sound different. Have someone videotape you (when you don’t know you’re being taped) to see the gestures and body movement that mark your personal style.

3. Are you mixing it up? Remember to hit the “Refresh” button. A top executive I work with recently stopped cold while rehearsing his speech and sighed, “I’m starting to get bored here myself.” Whether you add a cartoon or image to your PowerPoint, ask real and rhetorical questions–or walk a few steps to the side to tell a story. We live in a BlackBerry world. Adding variety to your visuals will keep you and your audience more engaged.

4. Do you think your presentation begins at 9 a.m., or the moment you drive in the parking lot? Recognize that “communication” begins the moment you arrive. Recall those auto execs arriving in their private planes to ask for taxpayer money. Thanks to social media, your actions (both good and bad) can wind up in print. So be kind to the receptionist, thank the folks backstage, and hold your tongue until you drive off the lot–no matter how clueless that guy in the front row was.

Mary Civiello is a presentation and media trainer and author of Communication Counts: Business Presentations for Busy People. She has been coaching executives for 10 years, after 20 years as a reporter and anchor for NBC News in New York.