Ever feel overwhelmed by a menu with more than 100 items on it, or confused when eight signs dangle over a single parking spot? You should. Human brains are pretty feeble. While computers can process millions of equations simultaneously, we can only make sense of so many options in a given moment. Often that means reducing your choices, sequentially tackling them one at a time, and contextualizing them so they're more intuitive.
For this reason, so-called user experience--the very important ingredient to create a successful, well designed, intuitive website--is actually universal to human communication, and ought to be used to develop more products.
Investors are just like you. That's why I think you should not underestimate the power of user experience expertise to help create your start-up fundraising pitch. If you think about your user's "experience," you'll focus on leading your audience through one concept at a time and ensure that through your narrative each new piece of information is delivered in a context that makes it easily consumable.
Literally, when making a pitch to investors, you should deliver one message per presentation slide, and relay information sequentially. Also, break key concepts down to the basics, and reduce the total number of ideas that are included.
One area where this is especially true: When you discuss the broader vision for your company. Often start-ups will have more than one phase to a business plan. First, they plan to penetrate a particular customer segment with a narrow service offering, and later they will expand to a larger potential market opportunity. At this point early on, the second phase probably can be envisioned in many different ways, each with great financial capacity.
If you have a lot of angles for your future business, boil them down to the core product or service. Then, sequentially outline how they might be deployed through various channels and mediums.
If the second phase includes entirely discreet businesses, pick one. Explain it. Then explain the second one. And so on. Don't cram all of your ideas into one talking point.
Remember that the more concepts you pack into your message, the fewer people will actually understand it.