I have used this assignment in junior high creative writing and high school ESL classes.
Students choose a genre and a basic plot pattern and answer questions to guide them through forming a complete story in their chosen genre. Students then create an outline using a Plot Diagram (available on my page for free). The numbers on the Plot Pattern worksheets which seem out of order line up with the numbers on the Plot Diagram.
Then students write a complete story, peer edit, revise, and "publish".