To improve your grades in the NPTEL Applied Thermodynamics course, focus on mastering the fundamental concepts of thermodynamic systems, processes, and cycles. Develop a strong understanding of energy conversion, efficiency, and entropy. Practice solving numerical problems and case studies, and review video lectures, notes, and assignments regularly. Pay attention to key concepts like heat transfer, refrigeration, and power generation, and apply them to real-world scenarios. Participate in discussion forums and clarify doubts with instructors or peers. Additionally, work on visualizing thermodynamic processes using diagrams and graphs, and attempt previous year's assignments and exams to assess your knowledge. By staying consistent and persistent, you'll see improvement in your understanding and grades in the NPTEL Applied Thermodynamics course.