First of all, you have to flourish your grammar skills. You can take help of a book to learn or revise your grammar. You will have to practice a lot in order to make eliminate your grammatical mistakes. Besides, you should be able to identify grammatical errors in a sentence efficiently. If you don’t like to study from a book, you can take lessons online. There are many websites on the internet which can help you in improving your grammar. Furthermore, you can also give online quizzes to test your English grammar skills.
It is extremely important for you to learn as much literary terms as possible. You can use "A Glossary of Literary Terms" by M.H. Abrams to learn literary terms. After learning the important terms, you will be able to identify the errors very quickly.
You have to keep reading the work of different authors and poets in order to become well acquainted with the literature and the use of terms. Some of the recommended readings include King Lear of Shakespeare, Paradise Lost by John Milton, Canterbury Tales by Chaucer, Rape of the Lock by Alexander Pope, Gulliver's Travels by Swift, and The Odyssey by Homer.
You must buy an anthology of English literature so as to familiarise yourself with the work of authors because of the questions in GRE Literature tests come from it.
You should also learn the famous lines and passages from the Bible as many questions can be asked about them.