Unless you are certain you can maintain motivation throughout all of year 12 to do 4 hours of study everyday, start with something smaller.
Year 12 is by far the hardest, but yet absolute best year of school. You will challenge yourself and go through highs and lows. The trials are definitely the most eye-opening experience in relation to the HSC.
My main bit of advice would be go hard from the very start of year 12. The only way I have the ranks I do now (top 3 for everything) is because I played it smart from day 1 of year 12 whereas many people in my cohort didn't care a lot about term 1 assessments and only really started trying during the half yearlies. You would honestly be so surprised how important a 15% task is when you're in the last term of year 12. You going well in that task at the start of year 12 can be the difference between being ranked 2nd or 7th. It sounds dramatic but ranks are EXTREMELY important during year 12.
Also, play the system smart. For in class assessments lots of my teachers used past HSC exam questions. Have a look at some and if you cannot be bothered to write answers for all questions plan answers.
Remember, during year 12 you are competing with your peers. As in, if someone is close to your academic ability, DO NOT HELP THEM!
You will learn about Survival of the fittest in year 12 bio and honestly year 12 up until the trials is exactly like that! (hahaha)
As for bio, it is very hard. It is the subject I put the most time into and still only get average marks. For bio try obscure learning techniques.. draw labelled diagrams, tables, flowcharts and paste important bits of info around your house. Eg: On my pantry door is information about the immune response, famous scientists, DNA replication etc.
After the trials try and work out your uni preferences and submit your applications, including scholarship applications ASAP. There is nothing worse than the night of graduation having to write a portfolio for a scholarship application that is due in 2 days time. (personal experience)
I wish you the very best of luck for year 12!!! The next 12 months will be very challenging but also rewarding!
Oh and also, another bit of random advice: Involve yourself in as many school based extracurricular activities as possible! Especially if you plan on applying for scholarships.
