I have made a PPT that contains a lot advice on how to improve your language for IELTS. It most relates to the IELTS Writing Exam, but it could be applied to other parts. Key lessons are avoiding IELTS phrases and upgrading boring or repetitive language.
The BIG List of IELTS Speaking Questions [by topic]
[Speaking Part 2] Describe a Prize
IELTS Speaking Questions: Health
The Advantages and Disadvantages of Apartment Blocks [IELTS Writing Task 2 Sample Answer]
Describe a Close Friend [Speaking Part 2]
Do You Need to Provide a Balanced Answer to Agree/Disagree Questions?
Describe a Historic Place [IELTS Cue Card]
3 Mistakes You Should Avoid to Boost Your Writing Skills