How should I answer an exam essay question?

When it comes to writing your essay, there are a few steps which you can follow to produce a clear and well-thought out answer. Before you begin, read carefully through the three options in the exam paper. Choose the one that you feel most comfortable with, and which would best suit the vocabulary that you know. Let's look at the following question:
Une ville que j’aime Écrivez un article. • Décrivez ce que vous avez vu et fait la dernière fois que vous avez visité cette ville. • Expliquez pourquoi vous aimez cette ville. • Dites quels sont les inconvénients de vivre dans une grande ville. • À l’avenir, voudriez-vous habiter en ville ou à la campagne ? Pourquoi ?
Look to see what style of essay the examiners are after. Here, you are being asked to write an article, but options can include letters, emails, or the continuation of a story amongst others, so make sure to check as this can affect the structure and language that you use!
Next, read again through the bullet points, ensuring that you notice all of the details that you are being asked to include. See the first bullet point, for example, which asks you to describe both what you saw and did the last time you visited the town. Paying close attention to the bullet points not only provides you with a structure which you can follow when it comes to writing out your essay, but can also guide you with the tenses that you use. In this question, the first bullet point is asking for the past tense, just as the second and third points are looking for the present, and the fourth for the future and the conditional. Within these guidelines, try to provide as much variation as possible, using the passé composé, the imperfect and even the pluperfect if you can in the first section, and the future and simple future (aller + infinitive) in the fourth. It might help to write yourself a check-list of the tenses that you would like to include when you get into the exam so that you don't miss any, as a wide range will impress the examiners! This rule also applies to your use of vocabulary: try to be as varied as you can, and avoid repeating the same words over and over. Now is your chance to show the examiners just how much you know!
Once you have established the tenses that the examiners are after, see if you can incorporate other structures into your answer. One example may be the use of a 'si clause' (imperfect + conditional, or present + future). With this particular question, a si clause could work well in the third section, when you talk about the inconveniences of living in a city, e.g. 'S'il n'y avait pas autant de voitures, la ville serait plus tranquille.'
Once you have written your essay, make sure to check it through very carefully, correcting any errors in spelling and grammar e.g. verb endings or agreements. Be wary in particular of irregulars and verbs which take être rather than avoir in the passé composé, as these can sometimes catch people out!