Essay questions and topics can change from year to year, but in some cases it may be helpful to start writing early. I'll share my own personal strategy - this worked well for me, but may not work for everyone.
When I decided to apply to b-school, I took a look at the current year's essay questions from some of my target schools. I didn't apply that year but kept those questions in mind. I then started to write out possible answers to those questions in a notebook. I wrote in it as I was "inspired" to - it was kind of a b-school essay journal. When I remembered certain things that happened at work or in other areas of life where I had leadership experiences, I wrote in this notebook. Two years later when I was ready to actually apply, I utilized this notebook and reviewed it as I crafted my essays. I had absolutely no writer's block by the time I sat down to do my application. By the time I gave my essays to someone to edit, he did not have one word of advice for me. I had spent so much time thinking about my experiences and recording them, that I had no problems putting my thoughts to paper and picking the best experiences for the essays. It worked for me - I attended Harvard Business School.
It may not be "safe" in the sense that you are thinking to just write out answers to essay questions before the new questions come out (because the essay questions can change, although several are rather standard - just reworded sometimes). However, I think it's a good exercise to reflect and start writing early if you have the time. This exercise is good not just for applying to business school - but simply for personal growth reasons.
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