Talking isn't good enough for you. You need to show, demonstrate, present. No matter how flashy your visual aids are, they won't make up for a sub-par speech. In fact, used improperly they might make it worse! On the other hand, a well-placed picture can enhance an already spectacular performance (and if the picture is worth a thousand words, that's up to ten minutes of speaking you don't have to do!).
Fortunately, effective presentations are based on a few simple tips and principles that anyone can apply in Four Days, Four Hours, or Four Minutes.
Know your material. It's a great temptation to use visual aids as cues and reminders when you don't know your material. Let them lend you confidence, but don't let them give the speech. Everyone will know and respect your knowledge and know-how when you're explaining the props instead of using the props as crutches.
Design well. Don't use clashing fonts, don't make a graph that's catchier than your earrings or tie. The point of visual aids isn't shock and awe it's communication.
Enhance yourself, don't replace yourself. You should deliver the information. Read: no bullet points! Your materials aren't giving the presentation, you are. If your materials take over, you're just another person in a suit talking to a bunch of other people and waving a laser pointer. If you want to provide real value to your audience (or boss, or evaluator), give them you not your props.
Be interactive. Conversational, even. If a podium or laptop cuts you off from the audience, then it's better that they (if not the podium, the audience!) not be there at all.
Be Simple. After you've planned your props, posters, PowerPoint slides, what-have-you, cut out at least half. At least.
Practice. You don't want to drop your grandmother's china while talking about appraising valuable antiques.
Cues. When you're preparing on short notice, it's ok to choose visual aids that will aid you, too. But remember that less information delivered well is better than more information delivered poorly (e.g. by reading off a PowerPoint slide).
Utility. Props don't need to look as if they took a lot of time. They need to be effective.
Visualization. There's not much time to practice, but run through the presentation a couple of times in your mind beforehand, props and all. Studies show that athletes are more successful when they visualize their performance beforehand so are speakers after visualizing their presentations!
Watch this four-minute video.
If you really only have four minutes to prepare a presentation, play on your strengths. Humor? Use it. In-depth knowledge? Show it off (but don't be arrogant). Nothing? Pull out whatever is in your pocket and liken it to your presentation topic you can't go wrong!