Try to have the audience worry along with your characters and care about what happens next. As the suspense of your story builds, be sure to have some comic relief periodically. Approach the climax through ever increasing tension interrupted with periods of relaxation. Hanford, Puppets and Puppeteering, p. 101. The story has to seem real to you.
Children respond to sight and sound more than logic and plot.
Look over good children's books, or anthologies of stories. Notice how the stories paint word pictures and use the sound and rhythm and repetition of words. Repetition and Exaggeration has always been basic elements of story telling. Even when telling an old a familiar story from the Bible, you must use imagination and all the storyteller's skills to make it come alive. Use your imagination to make the story come alive as you prepare.