Effective study techniques for assimilating vast information for UPSC include the use of mind maps and visual aids to create connections between concepts. Summarizing chapters into concise notes and regularly revising these notes helps reinforce learning. Active recall through self-quizzing and flashcards can also improve retention. Group studies encourage discussions and different perspectives, which aid understanding. Setting clear, achievable goals and using a systematic study schedule ensures all subjects are covered. Furthermore, breaking down topics into smaller, manageable parts prevents overwhelm and enhances focus, making the process of massive information retention more achievable.