Trust me, so long as you actually try in the HSC it is nearly impossible to "fail". I think you'd have to be trying to fail to achieve that.
A good way I found to study was to make summaries, then read them over and summarise those summaries further, and then just keep on summarising them over and over and use the short summaries at the end to revise just before exams. Re-summarising work really helps the information stick in. For subjects like Food tech and business making summaries based on each dot point in the syllabus is a good way to do it.
Also take regular breaks. You can only focus for so long before you're mind begins to drift, I took a short break every half hour or whenever I felt myself getting tired. Go listen to some music, have a short walk or just have something to eat - it helps refresh your mind. Switching subjects or just topics every now and then also helps.
Maths;
Just do practice papers and questions as much as you can, because the more you practice the more prepared you'll be. I did advanced so I'm not sure what general is like, but it would probably help you to make short summaries of each chapter with just the main processes and formulas. Get as many text books as you can (those Excel Revise HSC in a Month ones are really good) so you'll have heaps of questions to practice.
English;
Start off by reading through as many notes as you can on your texts (class notes, bored of studies notes, text books etc) to increase your knowledge and understanding of the them. Then make summaries of the main points, themes etc in each of your texts. There's heaps of summaries on here that can help when you're trying to make you're own, and use google to
Collect as many essays as you can (get those Board of Studies HSC student answers books, it helps a lot to see how a band 6/5 response is structured) and go through and highlight important points and sentences that are worded really well. Pay attention to how they are structured as well because it will help you when you come to writing your own. For example, some choose to structure their paragraphs by text, others by theme etc.
Write you're own practice essays based on past questions etc, the more practice the better you'll get! You can start of by writing them with access to your notes and as much time as you need, but as you get closer to exams start practicing them in 40minute time brackets and without your notes. Have one generic essay that you can cut & paste/change under exams conditions to suit any question that you get, memories it and read it over as often as you can -- that's all I did in the last few days leading up the HSC exam.
Also, don't think that you cant study for section 1 and 2 of paper one. Practice as many past papers as you can to get used to responding to the type of questions you'll get for Section 1. That way you wont end up wasting time by writing half a page for just a 2 mark question under exam conditions. Have 2 or even 3 creative writing responses prepared ahead of time as well, and memorise!
Best of luck
