Legal is definitely content heavy and also requires rote learning (cases, legislation, international documents, etc - DON'T MEMORISE ESSAYS!! though you can always keep an essay plan memorised in the back of your head). Everything in the tests and HSC exam comes directly from the syllabus (especially the 'learn to' section, so what I do is write a response for every 'learn to' question from the syllabus, just so I have a general idea of what I will say in my exam). Your syllabus is your best friend!!
In terms of achieving a good result, just make sure you do tonnes of practice essays (tip: write a practice essay for every 'theme and challenge' dotpoint from the syllabus; especially for your Options). Make sure to get constant feedback from your teachers as well!!
I also made a document of LCMDI for each topic just so when it gets closer to the exams, I have all the evidence in one document, ready to be memorised. Hope this helps! :~)