I did my first presentation in front of a crowd when I was 15. Using an overhead projector, transparencies and pens. The slides were so bad that I had included entire paragraphs of text along some small pictures. My audience was so bored that half of them were falling off their seats.
Fast forward 10 years and after years of trial and error, I finally understood the purpose of slides. To complement the speaker and grab the initial attention of the audience. The only way to do this is by keeping the design of the presentation simple. No complex graphics, no long text. Just a couple of words, a number, an important and simple graph.
You might say that I'm biased because of my love of simplicity and involvement in design. Don't take my word for it, read this article. Vinod Khosla, a long time venture capitalist, also believes that simplicity is key to a successful presentation. So now that any doubt is out of the way, you can move on to simplify your slides.
The key thing to remember is that the slides need to complement what you are talking about. How often they change and what they include is up to you and depends on what you're presenting and the tone. If you want to be funny, use funny pictures that will make people laugh. If you want to be serious, use big clear type and emphasise with bold letters. Keep any graphics clean, simple and minimal. When you practice your speech, if you say "I don't expect you to read the graph/chart/process" (I hear this in most presentations) then remove it and replace it with something clear that makes the point. Data is good, but it's better to understand what you are talking about.
It's important to remember that the audience has come to listen to you, not read slides. Have fun and show them a good time, while communicating your key messages. If you are lucky, they will go away remembering a few nuggets of what you said. If you don't follow the above, then you might as well cancel the presentation and send the slides via email.
