You should be able to describe any employee as an animal at what they do.
Cofounder relationships are among the most important in the entire company.
You want an idea that not many other people are working on, and it's okay if it doesn't sound big at first.
For early employees you want people that have somewhat of a risk-taking attitude.
You never want to be in a place where an employee has vested 3 out of the 4 years of stock and they start thinking about leaving.
You want an idea about what you can say. I know it sounds like a bad idea but here's specifically why its actually a great one. You want to sound crazy but you want to ask to be right.