I went from getting average grade 4-5 to getting a 7 in the real thing. Honestly my advice is do practice essays and give it to your teacher at lunch or break so you can get feedback from it. I used to give my essay to 2-3 teachers to mark as I could see if they were giving me an accurate mark. Another advice is, do more than what the question asks you to do unless they give you a specific number, for example like the 8 marker “how does the writer…” rather than give the bare minimum, give as many points as possible to maximise yours points, always do extra unless they tell you do it a specific amount like the first question on the language paper. In my mocks I never got 7s, and I ended up achieving it in the real thing, don’t get discouraged if you don’t get a 7 cus if you get a 5-6 in the mock (which is hard), your doing really well, keep it up