The best way I find to revise any exam with open answers is to look over past A* exam answers. That's what I've been doing for this exam particularly, and it's helping majorly. You cannot access them off AQA's website, but if you can ask any teacher to log in and do it for you.
The answers' I've seen that do best often start with a short, concise intro that summarises their entire argument. Quotations are not whole, and often interspersed between sentences (I realise I am reciting common knowledge here).
Conversely, other answers go straight into their first point. As long as your introductory point quite literally references how it is answering the question then I assume you will receive marks.
Character analysis seems to be key in this exam for they bring out a lot of the key themes and constructs that will be talked about later in the essay. This can be anything from Macbeth's 'vaulting ambition' representing man's diabolical lust for power, the violation of God in 'Frankenstein' (artificial creation of life), and the vampire women in 'Dracula' as a representation of the danger of sexual freedom in females (ref. New Woman Movement). This is contextual analysis as well as actual analysis, so most times you can hit two birds with one stone, show that you know the text inside out and never talk in generalities- if you are referencing a certain event in the narrative describe what happens, and how that embodies your point. What does it represent? What are the author's intentions?
Quoting a critic's opinion often helps, as long as you subsequently disagree or agree with it. This is evaluation. Since a lot of the questions are based on opinion, this is likely where you will find most assistance, because the opinions are pre-made and you just have to justify why, with textual reference, you agree or disagree. This shows not only background reading into other viewpoints but also shows you can justify your own similar or dissimilar opinion.
If your introduction has explained to-the-letter why your answer is going to answer you question, you may not need a conclusion as a separate paragraph. As long as your last paragraph's point is a coherent answer that rounds off its point. If you have gone into your first point immediately, then it is often wiser to do a conclusion, so as to show why your points have effectively answered the question. I believe this is merely about preference.
Common questions are often where I become stumped, because there are literally so many possibilities. However, those doing Jan 13 like me should know that questions concerning 'warning against the dangers of ambition', 'macbeth and concealment', 'death seen as desirable in Dracula', 'Frankenstein's monster as his 'doppelganger', 'obsession being a significant element' and 'gothic villains making evil seem attractive' are likely NOT to come up, as these were June 2012s questions. However, do not rule them out; transgression, obsessions, and ambition recur in some shape or form.
Religion, the 'shocking nature' of the Gothic, 'Good vs. Evil, where Evil is victorious' are also common themes played in both A and B sections of the questions.
To those who are particularly pedantic, I do realise I am just re-iterating what has already been said. But I have tried to make it as simple-to-answer as possible. I myself will be doing the exam for the second time (I derp'd heavily the first time), but I have done great research into doing well on it. I'm doing it for those whose questions go un-answered and hopefully this provides a little more light into this annoying exam.