The topic--or introductory--sentence should concisely state the topic, informing the reader of the main idea of the paragraph. Think about your purpose for writing. Consider whether you are writing to inform the reader with facts, to sequentially describe an event, to defend your position or to tell a story. Your topic sentence could be at the beginning, middle or end of the paragraph. It should be a limited statement that clearly conveys the meaning of the paragraph. For example, if your broad topic is your childhood, then a limited topic sentence might be, "My childhood camping trips shaped me into who I am today."
Follow your topic sentence with about six supporting sentences. The role of supporting sentences is to provide additional details on the topic. Begin with your most important detail. For example, follow an introductory sentence on childhood camping experiences with, "Camping taught me responsibility." Provide more evidence with subsequent statements, such as, "I always had to pack my own clothes, gear and sleeping bag." Develop remaining sentences that offer details to support previous sentences and relate to the introductory topic.
Writing a good paragraph takes practice. It can be helpful to write your sentences on a graphic organizer, a blank chart with one box for each sentence, first to ensure your paragraph flows with relevant details. Mack Lewis, author of Scholastic's "Super Sentences and Perfect Paragraphs," recommends color-coding your supporting sentences to help organize your paragraph. Highlight your first sentence after the topic sentence in blue. Follow that sentence with one or two sentences offering more details. Highlight your supporting sentences in green. Follow-up with another supporting detail of your topic sentence, highlighted in blue. Continue with one or two more supporting details, highlighted in green. You should end up with a topic sentence, two blue sentences and two to four green sentences.
The final sentences of a paragraph conclude the topic by supporting or summarizing the main idea or by transitioning the reader to the next topic. Smooth transitions allow the reader to understand that one topic is finished and another is coming in the next paragraph. An example concluding sentence for a childhood piece might be, "Over the years, camping trips taught me to be responsible, brave and independent." In a longer piece where one paragraph is dedicated to learning responsibility and proceeding paragraphs discuss other traits like bravery or independence, the conclusion of the first paragraph should logically transition the reader to the next paragraph; for example, "Although camping taught me to be responsible, I also learned that bravery comes with experience."