Prompt: Can you provide a comprehensive and in-depth guide on how to write a winning startup business plan? Please include detailed step-by-step instructions, analysis, and best practices that would be useful for entrepreneurs and business owners. In your guide, please discuss the essential elements of a business plan such as the executive summary, business description, market analysis, competitive analysis, marketing and sales strategies, financial projections, and funding requirements. Can you also provide specific tips on how to make each section of the business plan effective and compelling, as well as best practices on how to tailor a business plan to specific industries or business models?

Additionally, can you offer a sample startup business plan that serves as a guide for aspiring entrepreneurs? Can you analyze what makes this business plan successful and effective? Can you also share some common mistakes to avoid when writing a business plan and explain how to address them?

Finally, can you provide guidance on how to update and adjust a business plan as a startup grows and changes over time, including best practices for measuring and monitoring progress and making data-driven decisions?