Fundamentally, what you want to know is what are the key themes of the work, what does it say about them, and how does it say it? You also want to know what is being marked: for instance there's no point going on about context when context gets no marks.
One thing that I remember getting a lot of attention (especially when discussing plays) was different interpretations of the text. For instance, for our Shakespeare, I talked a lot about the numerous versions I had seen of our play as each director had pulled different parts and themes out to put them on display.
Something that you can surprisingly ignore somewhat is actual textual analysis (given it's not on the markscheme.) I remember not using any quotes from the texts at all in my exam answers (aside from ones where a passage is given) as those answers didn't get any credit for language analysis. Instead, we learned quotes from critics about the works, again giving reference to alternate interpretations.
I've managed to dig out my coursework essays. They won't be exactly like what you want to write for your exam, but they still seem to be a fairly good example of the sort of argumentative writing you might like to do. I'll PM links to you.
Knowing what is being examined on each question is paramount, as I say. No point putting in context if that gets you no marks, and leaving out interpretations could cost you dearly, if its a lot of marks!
Oh, I ended up getting an A, on the current A Levels. Just so I don't look like I'm talking rubbish!