Before writing a comparative analysis you should have two different works to compare. It doesn't matter if you are comparing two different forms of literature, two different novels or two different approaches to politics.
In each case in your writing you should be able to give equal weight and research to both sides. You are going to juxtapose the views of both sides. You should take all the notes you have on the first one and all the notes on the second one and divide them into similarities and differences between the two sides. You should make sure your analysis doesn’t give too much weight to one side, of course it may be the side that you favor, and then a little less to the other. The last thing in your comparative analysis paper is to reach a conclusion that is proper for your analysis based on your comparison.