You want an idea that not many other people are working on, and it's okay if it doesn't sound big at first.

Aim to be the best in the world at whatever you do professionally. Even if you miss, you'll probably end up in a pretty good place.

Don't let the company get distracted or excited about other things. A common mistake is that companies get excited by their own PR.

These all sounded really bad, but they turned out to be good. If they had sounded really good, there would have been too many people working on them.

... the thing we see wrong with YC apps most frequently, is that people have not thought about the market first and what people want first.

If someone is getting every decision wrong, that's when you need to act, and at that point it'll be painfully aware to everyone.

Just put a little pin in your mind: when you cross 50 employees, there are a new set of HR rules that you have to comply with.