To tackle negative marking in UPSC prelims, candidates should adopt a pragmatic approach. It's important to attempt only those questions where they are reasonably confident of the correct answer. Practicing mock tests and understanding the marking scheme can build familiarity, leading to better decisions during the actual test. Additionally, it’s wise to manage time effectively, allocating specific periods to questions. This ensures ample time for the ones you are sure about while minimizing the risks associated with guesswork.