To build confidence before UPSC interviews, candidates can adopt several effective measures. Engaging in mock interviews with peers or mentors can simulate the experience and reduce anxiety. Understanding the current affairs and practicing common questions allows candidates to prepare meaningful responses. Additionally, self-reflection on personal strengths and achievements can boost morale and self-assurance. Staying updated on the latest government policies and societal issues is also crucial for informed discussions. Lastly, adequate preparation and a calm mindset can help candidates present themselves confidently and effectively during the crucial interview phase.