Dude, I feel you. My marks overall are basically the same as yours, and I feel so fucking disappointed but everyone I turn to just thinks I'm being petty lol. I've achieved well over 85 in every assessment so far, but in the half-yearlies, I was expecting a crack a few more 90s than I did - considering the amount of dedication I put into my study. Your ranks are good, so I think that if you work hard going onwards then you're well on track for a 99 ATAR. I think the only way, for me, to improve is to refine my exam technique - doing more HSC style questions in my study. I usually do better in exams than assignments, so I'll give you a few pointers. I start studying from the beginning of the term, well before assessment notifications are out. Two weeks before the assessment, all my knowledge is consolidated and I should not be doing anymore study. At this point, all I'm doing is refining my exam technique - going over as many past papers I can find. This includes a shit ton of organic responses to HSC questions - I never memorise an essay verbatim because I think it narrows the scope of your ability to tackle the actual exam question at hand. Feedback from teachers is crucial. Seek out your errors and work on them, it pays off.