I have recommended this website before but it is one that many of you will find very helpful. Go to Englishbiz to learn how to write a better essay. Even if you are in Year 13 it will be useful to have a look.
Whatever the essay you have to write, whatever its title or question, you won’t find a better way of tackling it than to write it in the form of a well-structured and well-supported argument. This kind of essay is easier to plan, more fulfilling to write and, for your teacher (or the marker) more interesting to grade.