it really depends on alot of things including the teacher. as someone who tutored people with english for a bit, you really start to get to a point where an essay can be good and on paper seem fine, but it just doesnt deserve 10, it can be written with good english, and have good points and evidence, but it just doesn't deserve a 10, whereas some essays you read them and say 'WOW this is a ripper 10/10'
but to try and be more helpful, when i was in a similiar situation, my 8's became 10's when i started to do 2 main things.
first of all is a really easy mistake to fix but dont use a $5 word when a 50 cent word will do. you see SO often people trying to just throw in big words into their essays just for the heck of it, and half the time people use this big words incorrectly! or it might be okay in terms of how it fits but its just not the right word for that sentence etc. obviously if you have a big word that fits then use that, but it is more important to use words that are the right word for what you want to say. language has subtle connotations and very often if you are just picking out words to use that you found on the internet you might get the connotations of it wrong. anyway thats 1 piece of advice
the other thing i did was (for text response) i stopped using ideas and evidence that were talked about in class, and i basically discovered my own interpretations and examples of themes. when you are marking a whole bunch of essays on the same book as a tutor (or a teacher) you see the same ideas and the same examples of them over and over, which can be fine, but if you want your essay to have flair and really stand out, you should go through the book yourself to try and find examples. sometimes you can find better things yourself, there are often ideas that teachers skip over or meanings behind text that they dont really think about/dont teach that are super fruitful. i remember for my ransom essay that i demolished in year 12 i wrote 1 whole page of the sac on the environmental descriptions that took place in like a 2 page flashback in the first couple of chapters that was literally not a talking point at any time during the 5 + weeks my class spent on ransom. try to find your own ideas and your own evidence for them and shit, idk. just try to give ur essay some flair.
also for context, back when i was doing VCE alot of schools including my own said to us that we shouldn't do creative essays. my schools logic and the teachers was usually alot of people do not prepare sufficiently for sacs and just do a creative one anyway because they think it is easy to wing then they end up doing shit. (despite these warnings a few people did creative and alot of them did shithouse LOL) BUT in that same vein, they also said that "if well prepared creative essays can be some of the best", and i think for the quiet american sac that my school had everyone who got higher than 48/50 (only like 2 of us) (we got marked out of 50) did creative. so i think if you are doing heaps and heaps of work and arent a bludger and you feel comfortable doing creative, creatives definitely can hit that 10/10 grade area and often alot of the 10/10 context essays are creative, but alot of the 7's 8's and 9's are expository
this is just my 2 cents from my experience with VCE, good luck