Tag: motivates your characters
One way to envelop your reader in a new world is to create (or appropriate) slang. Done clumsily, it can detract from your story, but Buffy and Firefly show how slang can add nuance to your story's universe.
Discussions about structure tend to offer formulas, though formulas often lead to formulaic stories. But an understanding of narrative structure is important: you have to know the rules before you break them.