Read your topic thoroughly and try to dig deep into all the aspects of the text. A comparative essay looks at two different works and comes up with differences and similarities. So, be sure to make a list of points that you feel are similar and common.
Read the two works attentively and note down literary devices, character development, tone of voice, mood and symbolism. It is important to see how the plot starts and ends, because you will be expected to write your essay according to the plot of two works.
Create a list of differences and similarities
This step is important as your essay will be based on it. You can make a separate list mentioning each point that is similar and that differs. If you know the basis of comparison (most of the times teachers tell you), you can create a list more easily.
It may be possible that there are not so many differences. In that case, you will have to spot similarities and include them in your list. Comparison does not necessarily mean that there should always be a difference. A comparative literature essay typically assesses how differently the two texts or works address the topic given in a novel or a play.
Develop a thesis
Create your thesis based on the list of differences and similarities you have spotted in the subject (poem, novel, etc.) and try to compare what aspect overshadows the other. You may find that the differences outweigh the similarities, so focusing on them throughout your essay will make a good thesis.
You can choose the method for your literature essay from alternating method. Alternating method is generally preferred by teachers and students alike as it places similarities and difference side by side, juxtaposing them to reach a solid conclusion.