Revision is an essential part of exam preparation, especially when it comes to optional subjects like Geology for UPSC. To efficiently revise Geology optional topics, you can follow the tips below:

1. Organize Your Study Material:
- Sort your study material according to topics and subtopics.
- Use color-coded folders or dividers to easily locate specific information.
- Ensure that your study material is well-organized and easily accessible.

2. Create a Study Schedule:
- Develop a study schedule that allows sufficient time for each topic.
- Allocate more time to complex or challenging topics.
- Set specific goals for each study session to stay focused and motivated.

3. Review Lecture Notes and Textbooks:
- Go through your lecture notes and textbooks to refresh your understanding.
- Highlight key points, formulas, and definitions for quick reference.
- Make concise summaries or flashcards for important concepts.

4. Practice with Previous Year Question Papers:
- Solve previous year question papers to familiarize yourself with the exam pattern.
- Identify common themes or recurring topics that are frequently asked.
- Analyze your performance and focus on areas where you need improvement.

5. Utilize Online Resources:
- Make use of reputable online platforms like EduRev for additional study material and practice questions.
- Watch video lectures or tutorials to reinforce your understanding of complex topics.
- Participate in online forums or discussion boards to clarify doubts and interact with fellow aspirants.

6. Create Visual Aids:
- Use diagrams, flowcharts, and mind maps to visually summarize complex geological processes.
- Visual aids can help in better comprehension and retention of information.

7. Teach or Discuss with Peers:
- Engage in group study sessions or teach concepts to your peers.
- Teaching helps reinforce your own understanding and identify knowledge gaps.
- Discussing topics with others can provide different perspectives and enhance your learning.

8. Revise Regularly:
- Break your revision into smaller, manageable chunks.
- Revise regularly to reinforce your memory and prevent forgetting.
- Conduct quick revision sessions before exams to consolidate your knowledge.

Remember, effective revision requires consistency and a targeted approach. By following these tips, you can efficiently revise Geology optional topics and enhance your chances of scoring well in the UPSC exam.