If you do want to get high results (40+), I'd advise you to study as much methods possible during the year, meaning go through all the chapters and exercises if you can. AN has a whole lot of tips and tricks regarding to tackle methods. There's always past methods exams to practice for at the VCAA website. I suggest you to buy the Derrick Ha Methods Coaching book, you won't be disappointed with that. If you think you are struggling at methods, it might be wise to get some tutoring.
A good example is some MHS kids who finish their whole maths book on the holidays. On top of that, they were already smart to begin with, and naturally, these are the ones who get 50 in methods.
Consequently, being naturally smart in methods will help you part way if you are somewhat less diligent in your studies, but if you want to get top marks, studying hard is the only option.