On the first stage you should analyze the text. Try to catch its meaning and author's purpose, make notes and comments. If you have to read several texts, think about how they connect with each other. While reading, you should also notice connections between your reading and the concepts you have studied in the class.
You reaction paper has a specific purpose, which you need to think about before writing. Find out what kind of reaction your professor wants to see in the paper -analysis and evaluation or your personal response. If you have doubts about it, ask your instructor. It is important to clarify this moment before you start.
Give yourself enough time for reading in order to come up with how to begin a reaction paper. Do not put it off, because you will need to read the text at least twice. First reading helps to familiarize with the text and the second gives ideas about the paper. Make notes and briefly describe your impressions about the reading, using such phrases as "I think..." or "It seems..." etc. Put questions to the text in order to define its key points, and start evaluating the material.
On the second stage you need to make a draft working with separate questions and ideas and then connecting these separate paragraphs. Start making the draft with freewriting. Simply put into words your thoughts about the text, express your opinion in several statements until you get the idea about how to begin a reaction paper.
Then try to explain these statements and produce proofs. After you finish freewriting, read the draft and choose the best statements supported by evidences. Decide from which angle you are going to look at the text and shape your thesis. It is one statement, which will clarify what you are going to criticize, analyze or prove.
Also you should start organizing the paper while it is still a draft. The reaction paper has a format of essay. For this reason it must have an introduction, body and conclusion. Make about three body paragraphs which will support your thesis. Devote each paragraph to a different part of text and find quotations to support your statements. Begin each new paragraph with a topic sentence. Do not forget to make transitions between paragraphs.
After you read the draft at least twice, go on to the last stage and make a final copy. Start with writing introduction. Do not forget to mention the title of text, its author, the topic of your reaction paper and your purpose. Write your thesis in the last sentence of the introduction. Then read the body paragraphs and check how they conform to each other and the paper as a whole.
In conclusion you should summarize all your ideas. You may also compare the text with other works written by this author or other works of this period or theme. Make sure that your conclusion does not contain new information.
When the final copy is ready, you should edit it. Reaction paper should be about two or maximum five pages. So make sure that what you have written is not too much. Check the paper for clarity, rewrite confusing sentences and add explanations if necessary. Then check grammar, spelling and punctuation.
After the final copy is ready, read again your assignment and make sure that your work meets professor's requirements. If you are satisfied with the paper, then it is ready.