Mad Libs are a great opportunity for designers to practice collecting information from learners and feeding that information back in the form of a story.
I was not feeling especially creative when it came to writing a story so I used this website: Story Generator (plot-generator.org.uk)
I then removed random words and replaced them with tags like %female name% which Storyline calls references.
Then it was merely a mater of collecting the desired words and placing them into the finished story when the user clicks "Write My Story".