What is the most effective way to revise for English Literature A level?

The best way that you can prepare for the English exam is by mind mapping key themes and considering what you would write about if a question on that theme came up, for example, which characters are associated with that theme, quotations that demonstrate that theme being present and how you might analyse those quotations. I would then urge you to memorise key quotations that can be used as evidence for points you make in an essay. I would suggest at least three quotes for each major theme. 

Once you have done this, and you have an in-depth knowledge of the plot and subject matter, then practice essays are your best friend! The more questions you attempt to answer and the more you practice you have of writing in timed conditions, the better your essays will get and the more confident and assured you will feel in the exam.