Writing stories is a great way for children to not only share their ideas and communicate with others...
but it also helps them enjoyably practice reading and writing skills.
Even if they dictate the story to you and you write it down under their illustrations, they still can make the connection between the spoken and the written word.
They also enjoy reading their own story over and over because they know the story and can figure out through context any words they have forgotten. Quentin (age 7) has been enjoying lately writing the adventure stories in which you have multiple choices, in which each choice leads to a different story.
This type of story requires the organizational skills of having multiple threads that all lead to a common ending. He has gotten quite good at organizing and numbering the pages correctly. Encouraging creating stories may be as simple as leaving a station available that has a large quantity of plain paper, drawing and coloring materials. We have also started a shelf nearby for child-created stories that we can pull out and read again and again. In addition, I have found that making a commitment to reading aloud to my children, even after they have master reading, many types and genres of books has encouraged them to explore and experiment making different types of books on their own.