A content-first approach to product onboarding focuses on understanding the user's story, goals, and journey before designing the onboarding experience. This involves creating a narrative structure that dictates how the story of the product is told, with a focus on people rather than products. The six key elements of an effective onboarding flow are: welcome message, identity for the product or company, problems to be solved, explicit value proposal, mechanics of using the product, and at least one call to action. To deliver content effectively, use voice and tone that speaks in a way people can hear, considering factors such as punctuation, grammar, emojis, and design elements. Ultimately, great content helps users reach their goals by providing a clear structure, focus on success, and effective communication.