These founders got rejected from Y Combinator four times. Here's how they finally got in.

"The goal with your pitch is to help the naive observer understand very quickly what it is you're doing and why it can be important or impactful," said Saroya. "A lot of the time, that's manifested in super concise writing. We learned those lessons the hard way."

It's especially important to not prop up your ideas using jargon language, said Saroya. "There needs to be no business jargon. You need to get down to the essence of your business narrative right from the start."

While it might sound counterintuitive, Saroya said the ultimate goal in applying to Y Combinator isn't getting in.

"You have to remember that you're there to build a business and not to get into YC. YC is a forcing function that helps you determine whether or not you are on the path to find product fit," said Saroya. "YC is not a school. You're competing in the real world for your company to survive. Focus on that."

"You have to remember that you're not applying just for YC, you're doing this for yourself," said Saroya. "The application is an exercise that is intended to help you crystallize your thoughts around what you're building. That's the whole point. So the YC application is useful irrespective of whether you get in."

"Being rejected from YC can be really painful," said Saroya. "But having to face tough customer feedback can be even worse. YC just helps you refine what it is that you're trying to achieve."

Three of the four times Saroya and Gray pitched their fashion application Stylekick, they received invitations to interview, but still didn't get accepted.

After they sold Stylekick and pitched their next business venture, the property insurance application Cover, they applied again. This time, the pair said they not only had experience selling a company, they had a better product fit.

"If you're coming into Y Combinator and thinking, 'YC is going to teach me how to do this'...that might the wrong approach," said Gray. "We had all of this experience. We had tried a lot of different things at that point."

Gray continued: "YC is an access to a network and resources. If you don't know how to turn your idea into an actual business, investors will know that. When you're an early stage or pre-seed company, you're a couple of people with an idea and you're asking for a million dollars. The only thing an investor has to go on is you as a founder. Having all of that additional experience really counts."

Both Saroya and Gray said they owed at least one part of their success with StyleKick to their repeated applications and interviews with Y Combinator.

"When you apply to YC, you have to know your numbers and your industry," said Saroya. "You have to speak plainly and communicate your ideas simply. YC is exceptional at keeping you honest with yourself about all the things that are going right or wrong."