When I meet with a startup for an investor presentation, I am usually the first external "marketing person" they meet with. (Understandable, no investors, no money, no marketing budget). Some CEOs are nervous about the daunting task (and cash expense) of getting all those marketing materials ready as the company expands beyond product development. Sales presentation, investor presentation, one pager, leaflets, website, introduction video, etc. etc. ("Do you do those as well?")
My advice: take things one step at a time. An investor presentation is a good place to start, since any investor presentation needs to include some sort of customer sales presentation as well. (Investors need to be sold of the product).
The company/product story is often not completely set in early stage startups. So, freezing the spec and commission a lot of money to all kinds of designers might cause problems down the road. A presentation is actually a useful format to play around with visual concepts. Graphical execution might not be the best, but things can look decent enough and are easy to change.
After you feel that the presentation starts to work, you can consider upping the investment in the design of other marketing material. But here, I would do things gradually as well.
When working with video and video producers/designers, make sure you have a version of the footage that does not include text (in a specific font, containing a positioning that could go out of date) and logos (that could be changed later on). Video footage can be useful for a long time.
In short, it is better to do things step by step, rather than all at once.
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