Here are the five rules you need to remember to create amazing PowerPoint presentations:

1. No more than six words on a slide. EVER.
2. No cheesy images. Use professional images from corbis.com instead. They cost $3 each, or a little more if they’re for ‘professional use’.
3. No dissolves, spins or other transitions. None.
4. Sound effects can be used a few times per presentation, but never (ever) use the sound effects that are built in to the program. Instead, rip sounds and music from CDs and leverage the Proustian effect this can have.
5. Don’t hand out print-outs of your slides. They’re emotional, and they won’t work without you there. If someone wants your slides to show “the boss,” tell them that the slides go if you go.

taken from:

• Free Prize Inside: How to Make a Purple Cow by Seth Godin
• Really Bad Powerpoint (and how to avoid it)