The document discusses techniques for writing effective sentences. It emphasizes that sentences are the basic building blocks of writing and good sentences are needed for good writing. It provides tips on how to take control of sentence structure by making sentences longer or shorter in order to make them more informative, effective and satisfying. It discusses different sentence structures like cumulative sentences and provides examples of both short and long, impactful sentences from literature. The overall message is that writers should pay attention to crafting individual sentences with care in order to improve writing.