Select a children's book that is appropriate for the child's age group and interests. Ideally, pick a book that is a reading level above the child's reading level to illustrate writing above his current skills. This gives the child something to model for better writing.
Determine what element of writing to teach the child. There are various principles of writing a child can learn from a children's book, such as story elements like setting, characters or sequence of events, flow and sentence structure. Select one area, such as story elements, to work around for the start of the lesson. You can then work through all the lessons using the same book.
Read the book aloud to the child. Since the book is above the child's reading level, she will need an adult to read it to her in order to understand the story. Or you can help her read it with you.
Give the children instructions for the lesson. For example, tell them to break down the story by beginning, middle and ending or to break down sentences into nouns, verbs and other parts of speech. Allow each child to work through the problem, but give treats as a motivation to keep trying. Write down the child's ideas and point out that she came up with those ideas and the words on the paper, making it her story.
Tell the child to organize the ideas. Ideas can include the elements of writing, brainstorming his own story or ideas relating to how the words and sentences are put together. If the child is very young, he might need help in the organization process.
Assign the child a writing exercise based on the book. The child can either write her own story based on the elements in the book or she can write a report on the book. This provides the child with writing practice. The child might write the various parts in different colors if learning about story elements, or she might write her own version of the story based on the plot. If studying sentences, she should consider the way the author constructs sentences and try to write in the same style. For example, if the author starts with actionable verbs, the child might also write sentences starting with actionable verbs.
Assign the child to edit her writing. In a class, students can exchange papers and peer proofread. Otherwise, the child can proofread her own paper and then have a sibling or parent read over it and give advice.
Tell the child to rewrite the assignment with the corrections and then read it again for flow. Ideally, flow should have a similar sound as the story that inspired the assignment. Flow is the way that words, sentences, paragraphs and writing as a whole come together and sound when read aloud. The style of writing, the proper use of grammar, the pace and the way an author transitions between ideas all contribute to the flow of a book and how it sounds when read out loud.