It can be daunting to revise for foreign language exams and often people don't know where to start. Trust me, I've been there. However, I've found that the best way to structure your exam preparation is to break down the exam into different skills that it examines, and then work on improving those. Your exam paper will probably be composed of a grammar section, a listening section and an essay section at the end. For each section you need to think critically about each one of the skills required and work on improving them individually in order to bring them all together to improve your overall grade for that section. For example the essay is not just assessing your writing, but many skills, such as your vocabulary, grammar, the authenticity of your language (how native it sounds), the fluidity of your text, syntax, and basic essay structure. Identifying the different skills that each part of the exam assesses and honing these skills is integral to achieving the best marks in my experience.