I ran a small VC firm with a regional focus and reviewed over 1500 business plans/pitch decks.

The worst failing in most pitchdecks is the lack of sensible summary financial projections. By this I mean, financial projections that omit working capital requirements, that underestimate costs, that underestimate capital required, that overestimate revenues--in short financials that are just a series of straight line projections. Projections dont have to go down to the level of how much you will spend in year 22 on stamps, but they do need to have coherence.

The second worst failing is a failure to appreciate the nature of the competiton chasing the same idea or the same customers.

The third worst failing is keeping everything secret. The truth is that most likely somebody far smarter than you probably already has your idea and your next idea too. You make money by planning and executing, not by ideas.

Fourth is ludicrous ideas about valuation by unproven teams with vaporware or brochure ware or an imaginary test bed level product. All of those things can become a successful business, but not if you start out imagining that a couple of patents or patents pending are worth $100 plus million.

Please feel free to get in touch if you would like to discuss this further.