Operating by trial and error mostly, we've evolved a tacitly agreed upon list of...

Operating by trial and error mostly, we've evolved a tacitly agreed upon list of the elements that make for a good fantasy. The first decision the aspiring fantasist must make is theological. King Arthur and Charlemagne were Christians. Siegfried and Sigurd the Volsung were pagans. My personal view is that pagans write better stories. When a writer is having fun, it shows, and pagans have more fun than Christians. Let's scrape Horace's Dulche et utile off the plate before we even start the banquet. We're writing for fun, not to provide moral instruction. I had much more fun with the Belgariad/Malloreon than you did, because I know where all the jokes are.
All right, then, for item number one, I chose paganism. {Note that Papa Tolkien, a devout Anglo-Catholic, took the same route.}