Build relatable and memorable characters. Part of what makes children's literature such a cherished memory for so many people are the characters that were children with feelings that were all too familiar.
Address issues that are age appropriate. Pre-adolescence is possibly the most awkward and uncomfortable phase of a lifetime. Creating scenarios that validate young concerns win major points with young readers.
Introduce new material. Young readers have an insatiable thirst for knowledge. Incorporating new words, new places, or new people into literature for young people boosts their capacity for learning.
Write stories that jibe with young attention spans. By the time children are in fifth grade, they have graduated from storybooks but may not be quite ready for lengthy chapter books. Keep the story's plot short. Remember that young readers are evolving.
Create a format that is appealing to young readers. A picture-on-every-page format is probably a little beneath avid young readers, but a well placed illustration in the background of descriptive writing is probably welcomed as children learn to create their own mental illustrations. Larger print is a good idea, as are brief and concise chapters in beginner's chapter books.