Examine different scholars' opinions of the text you're analyzing. For example, if you're analyzing Alice Walker's "The Color Purple" and you want to argue that this text has elements of genealogy, feminism and African themes, read the works of scholars who hold to this opinion as well as those who disagree.
Avoid generic thesis statements. Your thesis statement should be specific and arise out of the research you've done. Instead of writing "William Faulkner's work was an example of traditional Southern writing", you can write "William Faulkner's writings reflect the political and social tensions of the South during the early 20th century."
Write a list of thesis statements before writing the paper. This helps you get an idea of what you want to do with the paper after looking over the research you gathered. Before doing the research, you may have had a certain thesis statement in mind. You may want to change it, however, after getting more information.
Talk to your professor. He can help you come up with a clear thesis that will guide the rest of the paper. If you're analyzing F. Scott Fitzegerald's "The Great Gatsby," ask your professor about possible ways to approach the book. Your professor may advise you to examine the modernist themes in the book.