>tl;dr determination, creativity, and a good product demo.
Sure, but aren't those things that are normally expected of applicants? "Hack" implies a clever trick that routes you around the normal mechanisms. And, quite seriously, the only hack I found was beer.
If you copy those things, you'll have a good chance of getting into YC.
If you copy "Send Garry Tan beer," you'll look like "the guy that didn't have any original ideas, so he copied Apoorva" :)