Think about range of vocabulary, you should also check your writing for unnecessary word repetition you are graded on the variety of your language. You should note that this does not mean you need to use long, complex words, rather it means you should use precise words. The more you write, the more likely you are to make language mistakes. The more you write, the more likely you are to go off topic. The examiner wont read/grade anything that doesnt directly relate to the question. I should add that these are mostly band score 8.0 writing tips and are written especially for candidates who are aiming high. The moral is: the road to band score 8.0 often means doing the simple things well 1. The backbone is: The introduction : this should identify the question and outline your position. Dont rush it as it is the first thing the examiner will read. First impressions count.
Heres why: Examiners will only spend so much time looking at any essay. Write too much and they will read what you wrote less carefully. It is easier to read/grade a 300 word essay than a 400 word essay! What isnt a waste of time though is to look for mistakes you know you can correct the ones you normally make! The really practical thing is to have your own checklist in your head before you start writing.