The introduction should start broad and then get a little more focused. Let the reader ease into the text slowly. Introduce the general subject, move on to the more specific topic, and end with the thesis. For instance, I could begin with a sentence about eating food, move on to the pleasures of eating fruit, remark on the tastiness of berries – especially cranberries – and then go on to the health benefits of cranberries. I could end the introduction with my thesis, which is something about the polyphenol antioxidants found in cranberries.