Some common pitfalls candidates face while preparing for the UPSC include inadequate time management, lack of clarity on the syllabus, and neglecting to revise regularly. Over-reliance on one type of study material can limit knowledge. Additionally, many aspirants ignore the importance of mock tests and feedback, which are crucial for self-assessment and improvement. Missing out on current affairs can also lead to gaps in knowledge. Staying organized, maintaining a balanced study routine, and seeking guidance when needed are essential steps to avoid these pitfalls during preparation.