I mainly focused on case studies and exam technique. Knowing the basic content is essential but being able to show the examiner you know it and bringing in little real-world examples/details is very significant too. Once you start feeling confident with the basic content, or even before, start doing a lot of practice papers and exam Qs. From 4-markers all the way through to 12-markers, get teachers to assess them for you and try not to lose little marks. Good luck!