After browsing through Ronald B. Tobias' 20 Master Plots: And How to Build Them
I am tempted to finally give Joseph Campbell's The Hero with a Thousand Faces
a chance. As it seems, Tobias has written a helpful guide, complete with checklists (!), about the major themes of literature. An enlightening read. It's like putting on the X-Ray glasses. Like "The Method" for writers.
If you are into structure and universal themes like me, than this book, these books, are a must read. What you, me and everyone, including George Lucas, should keep in mind is that these guides shouldn't be a recipe. There are rules. And you should know them. But rules are there to be broken, in literature and screenwriting. That's mastering structure.