The natural next step after "Be a fuck-up," is naturally, not caring at all whether or not you get the job.
This may seem counterintuitive at first. As in, "If I don't care, I won't do a good job."
But that's not what I'm saying. Getting the job would be nice and all, but that's not why you're in the room. You're in the room to show them the shit you can do with those four pages in your hand. You're there to show them the work you put into these four pages. To show them that you made some frikkin' choices. That you're NOT BORING. That you're engaged with the material. That's why you're in the room.
Whether you get the job or not is soooo far out of your control that you shouldn't even be thinking about that AT ALL. The more you think about the job, the more your stupid brain starts spinning out of control with all kinds of crazy scenarios and stories about how you're finally going to get your new apartment and by a house for your mom. Guess what, you're not. All you're gonna do is walk into that room, and kill it. After that, who knows.