Essential skills for success in the UPSC interview include strong communication abilities, critical thinking, and a deep understanding of current affairs. Candidates should also demonstrate confidence and sincerity while expressing their opinions. Interpersonal skills are crucial, as the interview board assesses candidate temperament and adaptability. Additionally, being aware of social issues, political developments, and government policies is vital, as these topics often dominate discussions. Practicing with mock interviews can help candidates refine their responses and improve their overall presentation.