Hey!
I haven't got my score yet, so I can't really comment on how effective my strategy was, but here's what I did (and averaged in the 90s for my sacs):
As in all my subjects, I focused on the fundamentals. Don't bother on questions before you're sure that you understand them. Look for outside materials/notes/etc that guide your understanding, NOT questions. The more you understand, the better you will be able to answer explain questions, which form the majority of the exams. Also, the more you understand, the more you will be able to apply to questions that aren't the usual. VCAA seems to be heading in this direction more (although both papers this year weren't that hard).
Once everything is consolidated, work on commercial papers. Try to do them fast; I would finish each paper in around 45 minutes, because in the exam, you want to have heaps of time to check and consolidate your explain questions, and in the exam you generally go slower.
Hope this helps

PM me if you want extra tips/anything

Good luck