I've been teaching my kids to tell their own stories. We've been using the simple formula of: "Pick a good guy, pick a bad guy, pick a problem." I've also been introducing them to the oral traditions of our culture by telling them the story of Star Wars (which they've never seen).
So, here's my favorite story that the kids have come up with so far:
"Obi-Wan Kenobi got up in the morning and got dressed, but when he looked in the drawer... NO SOCKS! He looked in the dirty clothes... but no socks! He looked under his bed... and saw Darth Vader curled up under there, holding Obi-Wan' socks! Obi-Wan tried to get Darth Vader, but Darth Vader ran down the stairs and outside. Obi-Wan tried to follow him, but... he didn't have any socks, so he couldn't put his shoes on. The End."
The only thing I would add is Darth Vader saying, "Do not underestimate the power of the Dark Side." The Dark Side is just mean.