Yes, it's a weird title, but hear me out...
I know I'm not alone in my sci-fi/fantasy obsession, nor in my obsession with Regency/Georgian fiction. The thing is, it has occurred to me over time that they're pretty much the same thing.
The thing that interests most readers in sci-fi and fantasy is that a book in either of these genres is a world unto itself. It has its own rules, etiquette and reality that you simply don't get in everyday life. The same is true of period fiction. In its day, Pride and Prejudice was a fairly simple tale told eloquently. The same could be said of the rest of Austen's works, Thackeray's and most of the Bronte novels.
But, 200 years later, they are something else entirely. Entering that world is much like entering a Star Trek episode or a Pern novel. You get accustomed to the world over time, but it's not anything you are ever likely to see in real life.
Every great work of fiction is like that- a world to itself that is unlike any other. Some worlds are full of humorous mishaps, some of constant mystery and intrigue. That's what I think fiction writers should be striving for. Rather than just telling a story, try to set up an entire world. It's a tall order, but it's by far the best aspect of any type of fiction. If a work of fiction is too standard, too interchangeable, the world just doesn't need it.