The idea should come first, the startup should come second.
If you compromise and hire someone mediocre you will always regret it.
You need someone that behaves like James Bond more than you need someone that is an expert in some particular domain.
You can basically change everything in a startup but the market.
In addition to relentlessly resourceful, you want a tough and a calm cofounder.
Great execution is at least 10 times more important and a 100 times harder than a good idea.