And no, that doesn't mean do a crap job. It means go for it. Don't hold back, or play it safe, in the hopes that you won't make a huge fool of yourself if you get it wrong.
If you shoot for the middle, all you'll get is mediocre. That and the knowledge that you could've tried harder but you didn't.
So the next time you sit down to write, or work out a plot, or anything else in life, ask yourself. Am I doing everything I can to make this great? Am I trying to make my story fit in with what everyone else is doing?
Is there a crazy idea you have for a story that in your gut, you know it could work, but you're afraid to try it? Are you shoving it aside to write something more mainstream/"now"/generic? Ask yourself it that's really what you want to do, and if it's not, go for it. And even if you fail, it will be the kind of glorious failure that shows your heart, and what's wrong with that?