Which exam board are you on, and what are the question styles like?
I find English Lit. quite hard as well - I think the most important thing is to know the texts really thoroughly, and to show that you know them really well!
Also, though the question might ask something about a character for example, my teachers always say that the question always wants you to comment on the effect of the language, and how this influences how the character comes across to the reader for example.
So, try and get as much terminology in your essay as possible, e.g. sibilance, alegory, etc.
Also talk about the layout/structure if it's significant, for example comma splicing (using commas instead of full stops) might show that a character's thoughts are constant and unrelenting etc, or the use of one sentence paragraphs etc.
I always find it helpful to make lists or mindmaps of key terms and their definitions
The key thing to remember is always comment on the lanuage and the effect it has on the reader!!!!
But having said that, don't forget to talk about themes etc. as well!
Hope this helps!