macbeth

The best way would be to read the play, see a production (or failing that, a film that is faithful to the text) and make your own notes on characters, themes etc., then make up your own answers using some quotes. By all means read other people's answers to other questions to see how they lay them out etc., but answer the questions in your mocks yourself.

That way you are ready for any question. It's how we did it in the olden days.

You could learn off twenty essays written by other people and none of them might address the question you are asked in the exam. It is actually much easier, less time-consuming and more productive to do what I suggest above.