if anyone got a 7,8 or 9 in English lit and did Romeo and Juliet or inspector calls

I don't know if this is good advice but it worked for me; I tended to not put more priority on the themes and put emphasis on the characters. Knowing the characters, and what they say and represent is crucial and you'll also be able to talk about the themes easily if you know the characters. Also, to get higher marks; I've been told by a teacher to interpret things in a different way that not most would. It worked for me too. If you go for the cliches and have the same basic analysis that everyone else had then it wouldn't stand out and you'd usually get around the 5-6 grade. However, that being said, I am only in year 12 and had just passed my GCSE's and this advice may not be for everyone but it really worked well for me.

For inspector calls mr Bruff and mr salles are really helpful

Also maybe you could look at research papers or exemplars on the exam website and on jstor or google scholar