When sitting an exam involving the writing of essays, if you go through past papers will be shocked how frequently you are asked to write essentially the same essay question again and again. This is true for many exam boards - A Level, IB and university exams.
I think if you pick 10 common essay questions and really concentrate on learning to answer those questions, you will almost guarantee yourself a top grade.
In the A Level economics exam I sat decades ago, I was required to write four essays in three hours. Essays were never my strong point which is why I took economics. I wanted to learn how to write a good, punchy, well constructed essay. I picked the ten most common essay questions from the past papers, and really made a nuisance of myself to my tutor, handing in essays answering the same questions over and over, writing essay plans, trying to pack as many points into a co coherent narrative as possible until i could almost rant an essay in a speech.
I got an A, then the highest grade, and can still write a good essay in 45 minutes. I do it twice a day.