I just finished working with a freshman college student home from school after her first semester in a university engineering program. The student took Calculus in the fall and did not do as well as she would have liked, even though she had AP Calculus in High School. In a three week period I worked with her to identify her Calculus strengths, weaknesses and gaps. I then developed a customer development plan which we implemented over the course of her winter break that taught her what she did not already know and strengthen what she "sort of understood."
We worked through her school's practice final exam, ensuring that she not only understood how to do the work, but also understood the fundamentals in all of the areas that her school thought was important enough to include on the final exam. I introduced her to techniques that were not covered in her Fall class that will provide her with the ability to solve certain Calculus problems in a straightforward, repeatable manner where she could not even solve them previously (for example, techniques for solving definite integrals, set-up and approach for optimization problems, etc.).
Are you studying Calculus in College or High School? How can I help you master this subject?