To build confidence before the UPSC interview, candidates can take several practical steps. First, engaging in mock interviews can simulate the actual experience, helping aspirants practice responding to common questions. Knowing the personal background and achievements thoroughly equips candidates to articulate their journey effectively. Additionally, maintaining a positive mindset through affirmations or visualization techniques boosts self-esteem. Gathering feedback from peers or mentors helps identify strengths and areas for improvement, further solidifying readiness. Lastly, understanding the interview format and being aware of current affairs cultivates a sense of preparedness, instilling confidence in candidates as they approach the actual interview.