What should my mindset and approach be when tackling the exam?

Approaching A Level English Literature exams can be extremely daunting. Three hours simultaneously seems like both an eternity and not at all enough time to say everything you want to. Personally, the most intimidating element was certainly that I had no idea which themes/ideas were going to be tested on. After all, how do you prepare for each and every type of question?
Before even thinking about the texts you're studying, it's important to know exactly what it is you're looking for from these texts (aside from just enjoying reading them!) This comes down to what AQA refer to as Assessment Objectives. Fundamentally you want to answer each of these objectives in any question you approach.
Loosely summarised these are:A05 - Engage with various interpretations of the text and their respective weight/significance. (12%)A04 - What are the connections between this text and others that you have studied? (12%)A03 - Show that you understand the historical context behind the text and how it was received by the public at the time. (24%)A02- Analyse how the author/poet has used literary techniques to shape meaning. (24%)A01- Write your answer with sophistication, demonstrating that you are confident in your answer and that you are applying your own critical analysis of the literature. (28%)
Structure - It is important to have a logical flow to your argument. To do this many students (including myself) have followed paragraph structures such as PEACE (Point Evidence Analysis Close Analysis Evaluation.) This will allow you to interpret passages, unseen texts and texts seen in the classroom in a logical way and importantly allow you to answer each of the Assessment Objectives in every paragraph that you right!
Read around - As an English Literature student, you probably enjoy reading! So do what you enjoy, and read! 12% of your grade is determined by how you connect a text to others that you have read and for the most part it is this element that will allow you to push from an A to an A*. Furthermore this will allow you to develop a unique perspective, this will help you to stand out to the examiner. The more evidence you have, the more convincing your claim and the better your grade.
Express yourself - Don't succumb to a stale regurgitation of only the ideas you hear in class (particularly if you're a shy student that doesn't get heard too often.) Your own ideas (provided they are supported by evidence) are just as valid, even if they seem controversial. The more of yourself that you express, the more you will enjoy writing about the subject and the more fluid your writing will seem. This is certainly something that many students struggle with, but is something that can really make you stand out to examiners.