Increasing the difficulty level of solving previous years' papers can be a great strategy for UPSC exam preparation. It helps in building a strong foundation and improving problem-solving skills. Here are some effective strategies that can be used to progressively increase the difficulty level of solving previous years' papers:

Create a Study Plan:
- Begin by creating a study plan that includes a realistic timeline for covering the entire syllabus.
- Allocate specific time slots to practice previous years' papers, starting with easier papers and gradually moving towards more difficult ones.

Start with Easier Papers:
- To get acquainted with the exam pattern and question types, start with solving easier previous years' papers.
- This helps in understanding the format of questions and builds confidence.

Analyze Mistakes:
- After solving each paper, thoroughly analyze your mistakes and weak areas.
- Identify the topics or question types that you found challenging and focus on improving them.

Refer to Study Material:
- While solving previous years' papers, refer to relevant study material, textbooks, and notes.
- This helps in understanding the concepts and theories behind the questions, enabling you to tackle more difficult papers.

Time Management:
- As you progress, start implementing strict time management strategies while solving previous years' papers.
- Set a time limit for each section and practice completing the paper within the stipulated time.

Take Mock Tests:
- Once you have gained a good understanding of the exam pattern, start taking mock tests designed specifically for UPSC exams.
- Mock tests simulate the actual exam environment and help in improving speed and accuracy.

Seek Guidance:
- If you encounter difficulties while solving previous years' papers, seek guidance from mentors, teachers, or fellow aspirants.
- They can provide valuable insights and strategies to overcome challenges.

Gradually Increase Difficulty:
- After gaining confidence with easier papers, gradually increase the difficulty level by solving papers from more recent years.
- This exposes you to a wider range of questions and keeps you updated with the changing trends of the UPSC exam.

Remember, it is important to be consistent and dedicated while following these strategies. Solving previous years' papers is an excellent way to assess your progress and identify areas that require improvement. By progressively increasing the difficulty level, you will enhance your problem-solving skills and be better prepared for the UPSC exam.