Brainstorm the themes, technical approaches, patterns and important issues you see coming up in the films. It is a good idea to watch the films more than once, as connections will be more likely to reveal themselves after several viewings.
Come up with a broad, general topic from your brainstorm that you think is intellectually interesting, challenging and can lead to an argument substantial enough to meet the length requirement of the paper. General topics for films might include "violence," "the role of women," "mise-en-scene," or "history." Make sure that elements of the theme can be found in both films.
Ask a question based on the topic to help narrow it down. For example if you are interested in the role of women, you might ask, "Why are women in the two films objectified?" If you are interested in mise-en-scene, you might ask, "What do props, sets and elements of design say about the psychology of the characters?" If you are interested in violence, you might ask, "Why does one director show excessive violence and not the other?"
Answer the question to create your thesis. For example, "Props, sets and elements of design in (film titles here) show that the characters are burdened and troubled by social inequalities." An effective thesis statement is able to be argued for and against.