The thesis statement is the most important sentence in an essay. In a sense, the thesis statement is a one-sentence summary of the entire essay. The thesis should not just give readers a general idea of the topic of an essay but should present specific statements of each of the main ideas developed in the essay.
For example, the thesis statement for an essay on a short story should include the title of the story and the name of the author.
Be specific as you list each of the main ideas in the thesis statement, using key words from the topic sentence of each body paragraph.
Avoid just listing the main ideas in the thesis statement. Instead, show how the main ideas are logically related. In the thesis statement, present the main ideas in the same order that they appear in the body of the essay, and try using words such as "although," "as a result," and "but" to suggest the logical connections among the main ideas.
In Maya Angelou's "Graduation," Marguerite Johnson's sense of pride in her academic achievements and upcoming graduation is challenged by the commencement speaker's stereotypical views of African-Americans, but a familiar song renews Marguerite's sense of accomplishment while giving her a greater awareness of the struggles and achievements of her ancestors.
The thesis statement is expressed as just one sentence, gives readers a specific sense of the main ideas, and indicates the logical connections among those ideas.
Does it take a lot of writing and rewriting to formulate an effective thesis statement? Yes. But it should help if you come up with the main ideas for body paragraphs before you try to write your thesis statement.