When I say succinct I mean if anything isn't 100% making your point, don't write it! I don't introduce texts like In X text, X speaks about X. This can tell us X. I just write X text uses X technique to tell X. My essays are 1200+ though... just look at one of your essays, chances are theres a fair bit of fat there which isn't directly earning you marks just making it sound a bit nicer. Don't introduce the text, your audience is a hsc marker who would know the texts backwards and doesn't need to be told.
Keep going through your essay and trimming fat, then you find yourself another X number of words for another text and stuff...