If you could give your best revision tip for exam preparation what would it be?

My best tip for exam preparation is to work your way through the course specification. This gives you the best understanding of exactly what you need to know for the exam, for example all the definitions you either need to know or not, that the course textbook will not tell you. This saved me a lot of time and stress during exams as I was able to cut a lot of information from my revision notes that I thought I was meant to know as it was in the textbook, and I could use this time to learn and understand the information that I was actually required to know.