Most people compose PowerPoint presentations in PowerPoint. Here is the danger with this approach. It encourages you to add special effects while creating your slides, and you can quickly overwhelm your presentation with fonts, colours, animations and transitions. The PowerPoint quickly becomes more about the cleverness of the program than about the content of the presentation.
If you find yourself falling into this trap, try this idea. Don't do the initial composition of your presentation on a computer. Instead, create it using a block of Post-it Notes. Sketch out your slides, one note per slide. Use small Post-it Notes to make sure that you don't try to cram too much content on each slide. Find an empty section of wall, or pin up a couple of pieces of bristol board, and layout your presentation storyboard style. If you are collaborating on a presentation, this works even better, since your whole presentation can be seen at a glance, and team members can easily add an rearrange slides. Once you are satisfied with your presentation layout, transcribe it straight into PowerPoint, using only one font, one colour, and no animations or special effects.
Run through the presentation in this clean state. I'll bet that it is pretty good. Now, with great restraint, consider adding a few effects to a few slides, only if the effect adds something to the presentation.
Here are a couple of instances where I allow myself to use special effects. I will use a special slide transition between sections of a presentation to tell the audience that we are entering a new chapter. I will animate just one or two points per presentation for emphasis. The key is to limit the animation to a couple of points. If you animate everything, how will your audience know when an given animation is special!
Give it a shot, I think you will be pleasantly surprised. Let me know how you make out.