To enhance retention of theoretical knowledge for UPSC, aspirants should focus on active learning techniques such as summarizing, teaching others, and applying concepts to real-life scenarios. Utilizing visual aids like mind maps and flashcards can also significantly improve memory recall. Regular reviews spaced out over time, known as spaced repetition, help reinforce learning. Incorporating mock tests allows students to assess their knowledge and identify weak areas requiring further focus. Also, discussing concepts with peers fosters deeper understanding and critical thinking, essential for the analytical demands of the UPSC exam.