As much as the school tries to push you to get high marks on your coursework, remember the EXAM MATTERS MORE!!! You can't get a higher overall grade than the grade you get in the exam (if that makes sense).
But if you get an A* in the cw that's a C already.
In the exam, consistency is key, you have to pick up enough marks in each question you can't rely on doing amazing in your best question.
I did AQA by the way.