To get a good band at the IETs examination you need a good knowledge of academic vocabulary, you should be able to use connectives and coordinators, use phrasal verbs and idiomatic expressions. You should also practice with sample prompts for writing.
Play these games and start your preparation. Discuss this in our community.
First read the writing prompt and the answer here and then learn the vocabulary. After that play the game to test your knowledge. Playing the game repeatedly can help you internalise these things.