All you do is add two more verses to the poem following an A B C B format. Keep it simple and simile related to the last verse.
An A B C B format is where the second and last line in a verse rhyme
Start!
There once was a man
Who had a bad dream
When he woke up
he let out a scream
His scream was so loud
As you can see
His cat woke up
And ran up the tree
