While reading a given novel (we read Johnny Tremain), students will put sticky notes into their novel each time a big topic comes up. Big topics include: war, independence, growing-up, love, hatred, peace, etc. Students then generate theme statements based on the textual evidence from the novel. If you use the Reader's Handbook, you can use more ideas of big topics. I like doing it this way because I want the theme of a novel to be more than one or two words. I want the students to articulate "what is this novel trying to teach me?"