We have a "storybook" with all of our core messaging. It's a powerpoint with a lot of slides covering segmentation, personas, products, and all the appropriate messaging that goes along with it. It can be a bit heavy (to download) but it's the one source everyone knows about. We host it on our internal sales enablement tool - Highspot.
There are a lot of messaging frameworks out there to choose from, but I take a bottom up approach: I start with the differentiators and proof points and then build my elevator pitch, value prop statements and long descriptions from those foundational components. I also use the rule of 3 for my differentiators and proof points. If you find yourself with a laundry list of differentiators or proof points, start looking for similiarities among those components to create larger "buckets" so that your audience has an easier time remembering your message.
These are all interrelated.
Messaging: Includes value propositions, your story, and pitch. Also includes things like naming, alternatives, and taglines.
Value Proposition: These are the top benefits you want to focus on for your product based on customer and competitive unput
Pitch & Story: These should be the same. Your pitch about the world before your product, the current approach, why it’s bad, the business consequences, and the new world with your product should tell a story. This story should hit on your main messaging points and value propositions.
Hope that helps!
I'm out of time, but real quick, Patagonia and Apple are favorites of mine. They both have brands that stand for something, and they continually demonstrate their commitment to their vision in their actions. On top of that, they both have high-quality products.
I believe that product and marketing are two sides of the same coin–you can't be a successful, sustainable business without one or the other.