Aspirants utilize visualization techniques to enhance memory retention of crucial facts for the UPSC exam by creating mental images or mind maps. These techniques allow candidates to represent information spatially, making it easier to recall during exams. Associating data with vivid images can improve retention and retrieval efficiency. Techniques like flashcards or diagrams can also simplify complex topics into digestible visual formats. By incorporating these methods into their study routine, aspirants enhance their ability to remember critical facts, leading to improved performance in both the written and interview stages of the exam.