The short story "Winter Dreams" by F. Scott Fitzgerald is a useful text to intro into a unit on The Great Gatsby. Or, if you are looking to developing thinking on authorial style, it's a way to look at Fitzgerald's writing without having to read an entire novel. The story is available on many websites online.
This is a writing prompt in which students have to describe Fitzgerald's writing style using evidence from the text. It also incorporates an optional writing frame for students who struggle with organizing their thoughts in a coherent manner. It works well for scaffolding/differentiating your writing instruction in the classroom.