The steps for analyzing tone in order

1. Select only the key words and phrases—ones that reveal something significant about the author, the subject, or the audience. (Write these words in the left column of your journal.)
2. Pay attention to the context and the subject of each of the words you choose. Ask yourself,
a. “What is the author referring to?” and
b. “What else is happening before and after this particular word or phrase?”
3. Categorize the evidence you have gathered. Group words and phrases by meaning, by
effect, by context, or by some other criterion you establish. This categorization will help
later when you write your commentary and, eventually, your essay.
4. Comment on your evidence by using the rhetorical triangle. Ask yourself,
a. “What is the author revealing about himself (or the speaker)?” or b. “What is the author revealing about the subject?” or
c. “What is the author revealing about his intended audience?”
5. Always include commentary on the author’s purpose. Discuss whether or not the author is achieving his intended purpose, and why. (If possible, comment on the tone that the author reveals or the mood that he creates.)

Hope this helps :)