You need to describe the experience adequately. The reader needs to be given enough detail to understand the context in which the experience occurred. However, it is not enough just to describe the experience in great detail. You also need to analyse and evaluate the events and the thinking processes involved. You should aim to consider deeper levels of meaning, exploring moral, ethical, social and/or professional issues.
Take time to organise and structure your writing. Try to focus on what was most significant about the experience, and relate it to aspects of your course and future career. Be careful that your writing does not seem to simply drift without direction or focus.