Allocating sufficient time for revisiting topics and practicing answer writing is crucial for effective studying and preparation for UPSC exams. Here is a detailed plan on how to incorporate these activities into your study plan:

1. Understand the importance of revisiting topics and practicing answer writing:
- Revisiting topics helps in reinforcing knowledge, understanding concepts better, and filling any gaps in understanding.
- Practicing answer writing improves writing skills, time management, and helps in understanding how to structure and present answers effectively.

2. Divide your study plan into specific time blocks:
- Allocate specific time blocks for revisiting topics and practicing answer writing in your daily and weekly study schedule.
- Ensure that you have dedicated time for each activity to maintain a balanced approach.

3. Prioritize topics for revision:
- Identify the key topics that require more attention and prioritize them for revision.
- Focus on areas that you find challenging or have a weaker grasp on.
- Allocate more time for difficult topics and less time for areas that you are already comfortable with.

4. Create a revision timetable:
- Break down your syllabus into smaller sections or topics.
- Assign specific time slots for revisiting each topic.
- Ensure that you have a balanced distribution of topics over the week or month.

5. Utilize effective revision techniques:
- Use active learning techniques such as summarizing, mind maps, flashcards, and teaching concepts to others.
- Review your notes regularly and highlight important points for quick revision.
- Solve previous years' question papers and mock tests to assess your understanding and identify areas for improvement.

6. Incorporate answer writing practice:
- Allocate specific time for practicing answer writing every day or at least a few times a week.
- Choose relevant questions from previous years' papers or practice sets.
- Set a time limit for each question to simulate exam conditions.
- Focus on clarity, coherence, and logical structure while writing the answers.

7. Seek feedback and review your answers:
- Ask someone knowledgeable to review your answers and provide feedback.
- Analyze your mistakes, identify areas for improvement, and work on them.
- Keep track of your progress and make necessary adjustments to your study plan.

By following these guidelines and incorporating regular revision and answer writing practice into your study plan, you will be able to allocate sufficient time for these activities and enhance your preparation for UPSC exams. Remember to stay disciplined, focused, and consistent in your efforts.