Hello, my first writing result was 6, then I got 7,5.
What I did are:
- read as much as best essay samples as possible: formal/informal letters, and writing task 2 essays
- set your standard format for intro and conclusion, and always follow it
- use different sentence structures: passive voice, conditionals, inversions and etc.
- for writing task 1 learn both formal and informal words and phrases, differentiate them well
- for writing task 2 I tried to avoid obvious connecting words like, first of all, secondly etc. Instead I tried to make the coherence look more natural, e.g. "further and even more importantly' (I strongly recommend you to read 'IELTS Write Right' PDF). Besides try to vary your vocabulary: learn synonyms of words that are related to topics like social problems, youth crime, education, traditions, technologies, health and etc (you can find further topics on the internet)
- start with the task 2, take time to plan and to proofread.
- do not waste your time counting the words, instead count the number of words of your first line and then count the lines. If it is about 170 for Task 1 and 270 for task 2, you are on the safe side.
- try to bring good and different arguments
- for the body part of the task 2, I stated my point, explained why I think so and then gave an example. Each paragraph had around 3 sentences.
This is all can remember.
Good luck