Fourth Graders have recently written their Long Composition for the state MCAS.  They skillfully told stories about a day that was a lot of fun for them.  They conscientiously planned their pieces, used coloful language, consulted dictionaries to correct spelling or choose a better word, and told stories you would not want to stop reading.  They must be very proud of their work.  Parent Debbie Souza shared this web site with teacher M Hutchings, thinking other parents might enjoy the information she gained from it:  Help Your Child Learn to Write Well   This is an archived site dated 1993, provided by the U.S. Department of Education. 

My advice:  keep writing fun, first and foremost.  If your child enjoys a good story, don't be limited by the paper version, go borrow audio books from the library.