Read your course notes and ensure you understand the exact form that your thesis title should take. Some professors may require a simple, descriptive title, others may expect the title to structure the thesis. You could look at thesis titles used in the previous year, as this will help you to establish the type of title you should write.
Write down the central argument of your thesis. Your title should identify the angle of your research and not just the topic. By including the central idea of your argument, you will produce a more specific title and avoid making a bland statement.
Use keywords in your title and if you are writing about a text, include the name of the work. If you are writing about a specific time period, ensure this appears in the title.
Write down a few potential titles. Check that each includes your main argument, are specific and include relevant key words. Show your potential titles to your classmates and teacher. Get some feedback, edit if necessary and decide on your final title.