Construct a good topic sentence that reinforces the title of an essay, offers an argument and previews the ensuing paragraph. For example, a topic sentence that begins a paper on Tupac Shakur might read: "Tupac Shakur's music profoundly influenced the social strata of Los Angeles by impacting the social and economic norms that traditionally pervaded society." This topic sentence is effective because it offers an argument and suggests that the following sentences will discuss the social and economic norms that were affected by Tupac.
Make sure that your topic sentence contains a controlling idea or argument. You should decide on a topic for your paragraph or essay, and then choose what type of statement that you want to make about the topic. For example, you might choose to write a paper on feminism. Now that you have a topic, you have to think of a controlling idea, such as the idea that feminism's prominent rhetoric mimics that of the Civil Rights Movement. In this way, you have both a topic and an argument that you want to express.
Place your topic sentences at the beginning of a paragraph. In very rare instances, you may place your topic sentence as the second sentence of a paragraph, but this primarily occurs at the beginning of a long essay in which the opening sentence is designed to grab a reader's attention. However, in general, you should place the topic sentence at the beginning of a paragraph, and it should transition from the previous paragraph into the subject matter of the following sentences.
Keep in mind that there may be exceptions when writing topic sentences. For example, a narrative within an essay may not call for a topic sentence, because this would interrupt the flow of the narrative. The important thing to keep in mind is that topic sentences act as guideposts for readers, summarizing important ideas and giving them a clue as to where your writing is going.