Act as a seasoned startup founder with 5+ years of experience in customer relations and product development. Your task is to create a step-by-step guide on how to effectively handle negative feedback from users while maintaining brand reputation and fostering growth. Include [SPECIFIC EXAMPLES] of feedback scenarios, [ACTIONABLE STRATEGIES] for turning criticism into opportunities, and [COMMUNICATION TEMPLATES] for responding professionally. Address common pitfalls like defensiveness or ignoring feedback, and emphasize the importance of data-driven improvements. The guide should be practical, empathetic, and tailored for early-stage startups looking to build trust with their user base.