One of my friends was a dropper and managed to crack AIIMS. When asked about his strategy, he told everyone that he would perform the self-introspection exercise. In this, he would take his NCERTs and open the index.
Point out every chapter and rate your knowledge out of 5 in each topic. Rate yourself honestly to determine your strengths and weaknesses. Perform the same exercise for every subject and you will realize how much you lagged behind. This will also instill in you a desire to study hard and overcome your weak points. Study at least one chapter you are weak at thoroughly every week. Soon those chapters will become your favourite.
So, self-analysis is the key!