The first of Paul Krugman's rules for how he works was "Listen to the Gentiles", meaning (as I applied it to creative work) get out of your bubble. The second is "Question the question". As he puts it:
... if people in a field have bogged down on questions that seem very hard, it is a good idea to ask whether they are really working on the right questions. Often some other question is not only easier to answer but actually more interesting!
The way I approach this for creative work is a little more obliquely than how Krugman has it. In creative work, few creators are preoccupied with theoretical questions of the kind that surface routinely in economics; they're too busy actually creating to worry about theorizing. Exceptions do exist — look at how François Truffaut successfully bridged the gap between critic and creator — but they're just that, exceptions.
The questions creators ask themselves tend to revolve more around how to achieve a particular goal. How do I get the audience to like my main character? How do I make sure everyone lives happily ever after? And so on. On closer examination, though, a lot of those questions may turn out to have a larger context. To wit: does your audience need to like your main character, or just be interested in them? (An interesting character does not have to be a likable one.) Is the assumption of a happy ending derived more from your attachment to your characters than it is a sense of what will best reflect the rest of the story? You'd be surprised at how your view of your own work changes when you put those questions to the test.
Another way to think about questioning the question is when it comes to the conceptual side of a story. When working on Flight of the Vajra I looked at the setting I'd created and said to myself, "Wait, if this happened in the real world, it would fall apart." That's when I realized the story was about the falling-apart of the idea, not about having it work by authorial fiat, and I ran with that instead. It didn't just make for a better story; it taught me how to think all the more constructively about how my stories could be put together in the first place.
The most important takeaway for this rule, then, seems to be that you should always reflexively examine all your own assumptions about how you create things. Why did I do this and not that? Why did I assume this story would be more interesting than that one? In short: Look at the questions you're asking. Find out where they come from. If you find complacency there, root it out.