The content of a child's essay can be organized into an opening, the body and a closing. Instruct kids to write an opening that proposes an idea or argument and gives clues as to what the essay will discuss. The body of the essay should be three paragraphs, each touching on one of the points hinted at in the opening. And the closing should sum up the content of the essay succinctly.
The composition of sentences is key to understanding how to write good prose. Once a child has finished an essay, ask her to point out the subject of a particular sentence, as well as verbs, adjectives and adverbs. Also, challenge your child to try different sentence style, such as lengthening a simple sentence or shortening a compound sentence.
A writer's voice is that unique quality that makes the writing sound a particular way. For example, some writers have a formal voice, some have a more casual voice. Ask your child to pay attention to his voice, pointing out where he sometimes writes in one style as opposed to another. This can help him determine which style suits him best.
Encourage your child to use new and challenging vocabulary words when she is working on a composition. Once she has finished an essay, have her go over her work and see where she could substitute stronger, more descriptive words. Kids can also focus on synonyms, adding adjectives and including hyperbole as a way of making their writing have more pizazz.