Hi Hannah,
I forewarn that I am no genius at school, but I can give you a few tips on studying and my general experience/s thus far.
I think in Year 11 it is important to set up foundations for next year, especially when those SACs seemingly fall from one day to another, as is often the case with Year 12 (currently anyway). It seems like you are doing this, so on this front I bear no umbrage.
Study cards are very effective in refining information, especially in the English based subjects. Just make sure these are organised, as when I was in Year 11 studying Year 12 Rev's by the end of year, all my flash cards were lost. Now I prescribe to loose-leaf paper as much as I can. This is only a matter of preference though.
Another way to study would be to actually practice essays, short answers or whatever it is under time constraints. This is essentially a simulation what it could be like on the day.
As a Year 12 student I constantly seek feedback with all my subject teachers. E.g. whether it is Further Maths (of which I am failing) or English (in which I am excelling) no matter how bad or how good I am going, I spend a lot of time conversing with my teachers. This includes after school sessions, lunch times, recess breaks etc... In Year 11 you shouldn't be expected to do all these things simultaneously, but it is healthy to adopt some of these approaches.
I have often been criticised by some teachers for "studying too hard" and trying to be a perfectionist at what I do. Such criticism led me to observe the efficiency of the way I study, e.g. video tutorials (YouTube), internet websites, more resources and removing distractions as much as possible by going to the local libraries, where I found I could produce nearly a day's more work than I could produce at home anyway.
Perhaps the most important thing is to have fun in Year 11; this is a year to find out your strengths and weaknesses in various subjects. Generally if you want to do well and truly believe it, as you do with your English based subjects and history, it is simply the average of law that one will excel in their endeavours.
Sorry if this does not help, all the best.