In terms of old exams, I'd stick to relevant questions from VCAA only. You'll see it with the VITTA and other company exams from the current study design, but they go off the course (or very near the borders of it). It won't be worth doing that for the old study design ones imo. The current study design company exams aren't too bad, they have their mistakes, don't assume that the answers are always correct. I can say for the VITTA ones at least, they're definitely out to try and challenge you.
If you're just solely passively reading notes it probably won't be entirely helpful. It's probably better to have a good think about some of the concepts, asking the question 'why' and then trying to answer it. That's not to disregard the value of notes, but ultimately knowing the content and then knowing how to apply it in the exam is the important part.
After sitting them once in exam conditions, you'll want to go through each exam you do carefully. Paying attention to things like what's the best way to answer questions, what kind of stuff are the assessors looking for. Take a look at the reports, they complain nearly every year of people not answering in the style expected e.g. things like not using key words correctly, not providing a justification when asked etc. Exploring any content that you're unsure of in a practice exam is probably obvious.
You'll want to develop techniques for common questions, e.g. desk checking algorithms and then how to deal with curveball questions - like desk checking that bubble sort algorithm in that other thread, that was ridiculously massive for a multiple choice question (edit: should say that question was from a VITTA exam, not a VCAA one)