Like anything else it comes down to being prepared. Knowing your business inside and out and being able to articulate your competitive advantage, what you do better, and what makes you unique is pretty standard fare.

This Business Week article provides great tips on being concise, compelling, and complete.

I cannot stress how many business pitches I've seen like this, where Phase One is "create widget," Phase Three is "profit!" and the crucial Phase Two is a complete unknown. Via Business Week

My favorite part of this article is The Pitch Critique Worksheet which provides 10 tips or a checklist to critique your pitch. Follow these steps and you will have a good start on communicating your business plan.

Need money? Be prepared, rehearse, and tweak your pitch until you feel confident.

BTW: the author offers a pitch critique.