Having been asked to write about a past experience , what tense do I use

L’imparfait would be used here as it can be used to describe things which can help visualise atmospheres or settings scenarios took place in and it can also be used to express opinions about the past. Pay careful attention however as when the verb être is used, it will be commonly in l’imparfait and NOT the passé composé as it is mainly used in a descriptive context or to express opinion