For most of the early hires you make in a startup, experience doesn't matter very much, and you should go for aptitude.

At the beginning, you should only hire when you have a desperate need to.

The idea should come first, the startup should come second.

I myself used to believe ideas didn't matter that much, but I'm very sure that's wrong now.

I believe in fighting with investors to reduce the amount of equity they get and then being as generous as you possibly can with employees.

Even though plans themselves are worthless, the exercise of planning is very valuable and totally missing in most startups today.

One of the pieces of advice that we give at YC is: try to work together on a project rather than just doing an interview.