The document provides examples of using different sentence structures to avoid repetitive and boring writing. It begins with an example of simple sentences all starting with a noun followed by a verb, such as "John went to the store." This becomes dull quickly. The document then shows how varying the sentence structure, such as using participial phrases ("Smiling, the man at the cash register...") and modifying the subject ("Returning home, the two put the groceries away"), improves the flow and impact of the writing. In conclusion, varying sentence structures is important to engage readers and avoid redundancy.