I actually use the same method as Gekko. I make concise notes on the different topics required, read through them and then rewrite them out to get familiar with the information. I only have to re-write my information out 2 or 3 times before I can remember it off by heart. Once you believe that you're confident, it always helps to do practice exam questions and apply what you have learned.
In my opinion, you should start making your Unit 3 Exam study notes now. This will help avoid cramming at the end of the year and you'll gain the benefit of re-enforcing yourself with what you already know. Seeing as Legal is your only 3/4, you can primarly focus on it. It's best to find out the areas that you are weaker in now so you can keep improving. The exam is in just over 3 months time so even if you just read through your Unit 3 notes every now and again, it will definitely help.