When i look at many of the essays posted on this forum, there is a major problem with clarity and, for want of a better word, 'crispness'. Essentially, there are so many study guides and resources that what will separate the 8s, 9s and 10s is the quality of your writing. Examiners want something that stands out, but they want to be able read through the essay in one go, not continually double back to figure out what you mean.
A couple of simple tweaks that will make your essay more awesome:
1. get rid of -ing words. Instead of 'Hector is driving', say 'Hector drives'-the use of the present tense is much crisper and engaging
2. cut out unnecessary words. Instead of 'not only....but also', say 'both'
3. Don't over-quote. Examiners don't care that you can say Priam is 'the ruler of Troy'...they know this already. You have to use a quote to explain something. e.g. Priam's role as 'the ruler of Troy' illustrates his immense symbolic and literal burden....
4. Don't use big words when you don't know what they mean. Build up a vocabulary that suits you and use these words in every essay.
Writing a clear, informative essay that satisfies the criteria (remember the one about linguistic and stylistic features) will always score higher that a pseudo-intellectual one.