"it".

Someone once told me long ago,
"If you have it, flaunt it. If you don't, just fake it."

And "it" doesn't refer to branded bags,boobs, or whatever you may think it is.
That person is talking about confidence.

His point is, you don't want everybody around you to know your insecurities. By "flaunt"-ing confidence, he doesn't mean being arrogant; he means self-assurance and all the marvellous feelings that come together with confidence. Just appear confident even on days you don't feel it.

Well, there are some drawbacks to that view I guess, but he got a point.