When thinking rhetorically it is important to hit on the main ideas of purpose, genre, context and the medium from which it is presented. You must consider all of said categories and expand on them. To think rhetorically you are not identifying a main idea or purpose in writing, but rather thinking about it from an array of distinct views. To do this will make it easier to identify what the writer is truly saying and the means from which he is saying it. To rhetorically analyze a piece you must break it down into its smaller components and use what you learn from the piece to identify the purpose of the piece. You must yearn away from agreeing or disagreeing with an argument and instead focus on HOW the author makes their claim. What tools do they use to make their claim? (quotes, opinion, etc.) How effective are these tools at persuading, entertaining, or informing the reader of the current situation? You must look beyond what the piece is actually saying and alternately look at just how it is saying it.