The best way to prepare for an English exam is (having read the texts) to explore the themes within the text, as these are likely to form the basis of the exam questions and it will also give you a more thorough understanding of the text. This can be done through drawing mind maps or having verbal conversations from which you make notes. From there you should look for literary devices or techniques within the text which can be analysed to show how the themes of the text are extended through the use of language, or how the techniques can change the way we read the text. It is a good idea to make note of a few quotations or key passages for each of the most important themes, so that you can quickly reference these in your exam.