Examiners read hundreds of essays. They suffer from "lexical fatigue." They have seen "I strongly believe" and "On the other hand" ten thousand times.
You could own the world's best carpenter's tools but still build a crooked table. The same applies to exam prep. The finest only works if you review your mistakes actively. Do not just "take" a practice test—dissect it. Why did you miss number 14? Was it the synonym? The accent? The distractor? IELTS Preparation Material
IELTS essays often revolve around common themes: Environment, Education, Technology, Health, and Crime. Look for "IELTS Topic Vocabulary" lists. Examiners read hundreds of essays
Each part of the test requires different strategies and targeted study materials. IELTS Preparation Materials for Test Takers (Free & Paid) IELTS Preparation Material