[header] How to introduce evidence in an essay [title] Set up the evidence in the first sentence of the paragraph. [step] The first sentence in the paragraph or section of your essay is called the topic sentence. It should let the reader know what is going to be discussed in the paragraph or section. 
If the paragraph is one of many in the body of your essay, the topic sentence should also link to the preceding section so the transition to a new section is smooth. [substeps] You can use 1-2 sentences to set up the evidence, if needed, but usually more concise you are, the better.