Candidates should be meticulous while filling the detailed application form for UPSC. They need to ensure all information is accurate and complete, including personal details, educational qualifications, and preferences for examination centers. Understanding the eligibility criteria and adhering to the specific format is essential. Any discrepancies or omissions can lead to disqualification. Aspirants should also pay attention to details like choosing the right optional subject, as this can significantly impact their performance in subsequent stages of the examination.