Aspirants can evaluate their performance in mock interviews for UPSC by seeking feedback from experienced mentors or peers who can provide constructive criticism. Recording mock sessions allows candidates to analyze their verbal communication, body language, and the clarity of their responses. Maintaining a checklist of expected competencies, such as knowledge of current affairs and ability to articulate thoughts clearly, helps in self-assessment. Additionally, comparing one's responses against a model answer can highlight areas for improvement. Regular practice and evaluation enable candidates to build confidence and polish their interview skills, essential for success in the UPSC selection process.