Common mistakes candidates make while preparing for UPSC exams include inadequate time management, lack of proper planning, and not keeping up with current affairs. Many aspirants also overlook the importance of mock tests, which help gauge preparation levels. Others fail to analyze previous year papers to understand the exam pattern. Furthermore, some candidates might get stuck in excessive theory without practicing answer writing. Lastly, a lack of proper revision can lead to incomplete coverage of the syllabus, hampering performance.