Basically fake it till you make it, means that you try to appear more successful than what you really are. Basically what did people do to make their startup appear bigger and more successful than what it really was.
I trust you mean getting business cards etc. There's a fine line between making good marketing investments and lying. I think embellishing your own success is a slippery slope.
Lying sucks energy and adds to mental clutter. Always be honest. It's hard enough to muster the creative focus you need to build something good without worrying about how you're "fronting." Better to hone your pitch so you can genuinely sell your idea to discerning customers.
Many businesses do profit from "appearing bigger and more successful" than they actually are. I call Bernie Madoff to the witness stand. Some smoke-and-mirrors is to be expected in industry but too many companies are flat-out "designing trust." Time is precious and I would rather spend mine earning customers' respect. The startups I admire are trying to be as tastefully transparent as possible.
I think rephrasing / reframing it as "show your better side" may sometimes be useful. I don't like the "fake" connotation; on the other hand, realizing others' reactions to you will correspond to your deportment, is useful.
Heck, your reaction to yourself will correspond to your deportment. This is why a central tenet of self-help is self-respect.
Thinking of this another way, most people are social creatures and have a certain tendency to "follow the crowd". If "the crowd" at a particular moment is you, and if you are demeaning or dismissive of yourself, they will pick up and respond to the message.
Sometimes -- often -- socialization not about some "absolute" of behavior. It is all about context, and about relative values defined within that context. Don't blemish your own reputation (or "brand", as they say these days), either by being a fake or by disgorging all its flaws. People aren't too interested in the flaws, unless it's something they can and need to learn from. And the situations and time for such sharing and learning are a limited part of overall social activity.
EDIT: Upon rereading, I guess I may have digressed a bit from the business / start-up context of the original question. But there, too, people are most interested in how you can solve their problems and make their lives better. Don't let the challenges you face overshadow your ability to do this for them.
