How do I write a personal statement for English Literature?

For your personal statement, you should show off your academic ability by using practical examples. For example, if you enjoyed studying Frankenstein for AS Level, you could talk about how this sparked your interest in Feminist Literary theory. This could link to activities such as involvement in groups like Amnesty International, and thus you are placing your passion for your subject in a real world context. 
Using quotes may be relevant, but don't be cliche, it won't impress the University you are applying to. Equally, keep your extra-curricular activities relevant- if you love unicycling, great, but how is that relevant? It probably isn't. Nevertheless, if you are head of your school's unicycling club, then this could be used as an example of leadership.