How can I improve vocabulary for unfamiliar IELTS topics?
Study words in useful topic groups—education, work, transport, health and the environment—but do not try to memorise entire model essays. Focus on broadly reusable language for describing causes, effects, comparisons and opinions. When you meet a new word, note its meaning, common partners and one original example sentence.
Then use it in a short answer or paragraph. If you cannot remember a specialised term in the exam, explain the idea using clear words you already know; IELTS rewards effective communication, not specialist knowledge.