I study at least every 2nd day properly, and I read outside the course through the prescribed textbooks. This gave me a 94.25 average last year, which is something I'm quite proud to achieve. Make sure that you do understand how each concept works back to front and how to apply it. This is not only true for Science, but for all courses. This can be done by completely every problem they give you (especially in Math courses) and revising the lecture before and after you've listened.
You'll have to dedicate a significant amount of time keeping your motivation high, which is quite similar to VCE. Although I did less overall work at uni compared to VCE, you do it in a quicker time period, making it very intense (especially around week 6 or assignment week). Expect to keep similar hours of studying if you were going to achieve a 95+ ATAR.
The biggest GPA killer at uni is a lack of motivation.