Methods to enhance retention of important historical facts for the UPSC exam include using mnemonics, timeline creation, and thematic summaries. Employing mnemonic devices can facilitate quicker recall of critical dates and events. Creating timelines visually depicts sequences of historical events, allowing candidates to understand context and causality. Thematic summaries establish connections between events and broader trends, encouraging deeper understanding. Regular review consistently reinforces this knowledge, ensuring that aspirants remain well-prepared for the history component during the examination.