For above a band 7 you will need IELTS vocabulary, this page shares some useful strategies and sources to improve your lexical resource.
To improve your opinion forming skills, check out the BBC, get a rough overview of the current affairs in each topic. For example, at the moment, regarding the environment the main topic is climate change -could you write 250 words about global warming? Likewise for the topic of technology, what do you know about artificial intelligence? You don’t have to be an expert but you do need to have an opinion, and that can only come from getting informed about the topics.
In summary it is advisable to be well versed with current affairs, have a global view of events, and bit of knowledge about each topic.
The two reasons why students fail IELTS:
English Language Skills
Did you know you can have excellent English language skills and still fail IELTS?
HOW CAN YOU BE GOOD IN ENGLISH AND STILL FAIL? -That’s unfair.
Well if it is impossible to understand your argument because of poor spelling and grammar, then the examiner does not know if you answered with the correct Task Response.
So the best way to prepare is to discover where your mistakes are so you don’t make them again.
And the only way to discover where your mistakes and where you lose points is to get feedback on your essays.
This way you start a positive cycle of improvement.
IELTS Exam Skills
How to overcome “MY MIND GOES BLANK” when facing an IELTS Task Two question.
How to organise your thoughts into strong coherent paragraphs.
How to write at least 250 words in 40 minutes on a topic you probably have zero interest in!
Unless you have solved these problems you will continue to fail IELTS.
I know this because I have helped hundreds, possibly thousands of IELTS students pass IELTS (I’ll explain more later in this page), and I can help you pass too.