To the novice a 10 side deck might sound like something you can knock out after dinner, but that is far from reality. I believe the best best pitch decks are distilled from a thorough well researched business plan. It goes without saying that a 50 page business plan takes considerable effort to compile. Concentrating that to 10-12 pages for most grants is a skill. Even more effort is necessary to hone back the most critical elements to a 10 slide deck. Make that a 10 slide deck that lends itself to "business theater". Your goal is to pitch a story that is honest, inspiring, clear and memorable. Paint the problem and provide a credible solution that will make money. Leave your angels exited by your ideas and your team and your product and most importantly leave them willing to write a check.