Maintaining a consistent level of performance while solving previous years' papers is crucial for success in any competitive exam, including UPSC. Here are some effective strategies to ensure consistency:

1. Time management: Proper time management is essential while solving previous years' papers. Allocate specific time slots for each section or question and try to stick to the schedule. This will help you develop a sense of timing and improve your speed and accuracy.

2. Practice regularly: Consistency can only be achieved through regular practice. Set aside a fixed time every day to solve previous years' papers. This will help you develop a routine and maintain a consistent level of performance.

3. Analyze your performance: After solving each paper, take the time to analyze your performance. Identify the areas where you faced difficulties and the topics that need more attention. This analysis will help you focus on your weaknesses and improve your overall performance.

4. Set realistic goals: Set realistic goals for each paper you attempt. Start with easier papers and gradually move on to more difficult ones. This will boost your confidence and motivate you to maintain a consistent level of performance.

5. Simulate exam conditions: While solving previous years' papers, try to recreate the exam-like conditions as much as possible. Sit in a quiet room, set a time limit, and avoid any distractions. This will help you get accustomed to the exam environment and improve your focus and concentration.

6. Seek assistance: If you encounter any difficulties while solving previous years' papers, don't hesitate to seek assistance. Joining a coaching institute or seeking guidance from experienced mentors can provide valuable insights and tips to improve your performance.

7. Revise and learn from mistakes: After solving each paper, thoroughly revise the solutions and make note of the mistakes you made. Focus on understanding the concepts behind those mistakes and work towards rectifying them. Learning from your mistakes is crucial for maintaining consistency and improving your performance.

8. Stay motivated: Consistency requires a strong motivation to keep going. Remind yourself of your goals and the reasons why you want to succeed in the UPSC exam. Surround yourself with positive influences, such as like-minded peers or mentors, to stay motivated throughout the process.

Following these strategies diligently will help you maintain a consistent level of performance while solving previous years' papers. Remember, consistency is the key to success, and with determination and perseverance, you can achieve your goals in the UPSC exam.