Crafting the message is the first step in the process. There are a few things to consider, even if it's only briefly, before messing with the shiny objects and bells & whistles.
What's the goal?
What are you trying to accomplish with your presentation? If it's to inform, make sure you have your facts straight! You should probably do that anyhow...
Who's in the crowd?
You have to speak the language and understand the culture. I'm not referring to different countries (although in some cases, it applies) but rather different sub-cultures. Old, young, male, female, likes, dislikes, familiar methods of communication - basically any background information you can gleam will be better than going into the presentation blind.
If you're presenting to school kids, are you speaking their language? What about college students? I cannot count how many classes I had in college where the professor was on a different wave-length (both way above and below) than the class. Have you ever seen Ferris Bueller's Day Off? Make it interesting! There are many easy ways to improve your presentation skills. Believe me, I understand that some people are better than others when it comes to presentations. With all of the free resources and help that is available now, I don't think there is a legitimate excuse to have blurry pictures, terrible contrasting colors, or spelling errors in your presentation.
Will there be internet access available?
This kicks you into a whole other realm when it comes to presentations. If you have internet access available at the location, make sure you test it out ahead of time - it's embarrassing to make everyone wait while you troubleshoot the technology (not just internet connection).
Tapping into multiple learning styles
What will people take away from your presentation in reality? If you have only text and read it to the class or crowd, anyone who learns visually or by practicing/doing probably won't retain a whole lot. Again, with so many free resources (pictures, video, themes, etc) it has become easy to get your point across effectively to just about anyone.
One way to promote next year's vacation Bible Camp is to do a video of this year's VBC. That's what we did, and you can see it here - http://vimeo.com/6013467