Applicants can use periodic reviews to sharpen their UPSC preparation by regularly assessing their progress and understanding of topics. This process helps identify strengths and weaknesses, allowing candidates to adjust their study strategies accordingly. Setting a routine for reviews, like weekly or bi-weekly evaluations of subjects, can also foster a deeper grasp of the syllabus and ensure that all areas are adequately covered before the exam. By noting areas needing improvement, candidates can focus their efforts and develop strategies for enhanced performance, ultimately boosting their readiness for the UPSC exam.