Allow yourself sufficient time to read the manuscript for the reaction paper. Do not skim through the document but read every page so that you understand the writer's intent. You might miss a critical opinion or fact if you hastily read a manuscript.
Make notes about each page as you read. Ask yourself what are the essential opinions and facts of the document. Question what are the main problems the authors pose to the reader. Use a highlighter, if you ideally have a copy of the manuscript, to mark the important ideas in the manuscript. Do not mark up books or documents that are irreplaceable. Take notes with separate pieces of paper.
List your feelings about what the authors have written. Does the manuscript anger you, or make you feel sad or happy? Is your emotional response consistent with what the author intended for his or her audience? Write first how you reacted to the writing and then make notes about how you think the author meant the reader to feel. Research, if the manuscripts are based on data, the veracity of the author's facts. Make notes from your research against any data that are not valid, What are the counter-arguments against the writer's opinion?
Gather your notes in order. Make an outline of your feelings or fact-finding research. The first sentence should list the author, title and date of publication. Next give a summary of what you have read. Place your primary feelings or refuting facts next in the outline. For example, "I thought that the author's story about the lost puppy was sad even though the writer meant the tale to be, in the end, happy and inspirational;" or "The writer's opinion about puppy mills was based on erroneous facts because the author did not take into account the evidence that the SPCA found behind the dog-fighting pit."
Extrapolate from the outline and fill out your responses with supporting statements. "The story was sad because the puppy's owner never found her dog even though she became a crusader for animal rights;" or "The author was wrong to write that puppy mills are harmless because the mills can leach feces into the environment and into ground water." Gradually build on the emotional responses or facts in the secondary sentences until you have a coherent narrative. Proofread the manuscript before printing the document.