Effective revision techniques for long-term retention in UPSC preparation include spaced repetition, summarization, and active recall. Spaced repetition involves reviewing information at intervals, reinforcing memory retention. Summarizing notes helps distilled content into essential points, making review sessions efficient. Using flashcards and testing oneself on key concepts aids in active recall, enhancing the ability to retrieve information during exams. Integrating various mediums such as videos, podcasts, and quizzes into the revision routine helps maintain engagement and reinforces learning, ensuring comprehensive preparation coverage.