Strategy
The first is pretty standard, you have to "work a lot."
The second is to "study physics and learn how to reason from first principles rather than reason by analogy."
That actually reveals a great deal about why he's started the businesses he has. In many ways, they're responses to the laws of physics. Here's how Musk explains what he's trying to do with Tesla:
“All modes of transport will become electric, with the ironic exception of rockets. There’s no way around Newton’s third law,” he says. “So the question is how you create a really energy efficient car.”
Tesla cars are incredibly light because of their aluminum chassis. Though the cars have some issues now, the shift towards electric vehicles is likely inevitable in the long run. SolarCity was founded with a similar idea in mind, that having sustainable energy is essential to mankind's survival. By making solar power more widespread, Tesla owners won't have to depend on utilities.
“I’m confident solar will beat everything hands down, including natural gas. If it doesn’t, we’re in deep trouble,” Musk said.
And SpaceX is built off the idea that unless mankind starts living on other planets, we're condemning ourselves to inevitable extinction. All reasoning from first principles.
His final piece of advice? To listen to negative feedback, especially when it comes from friends. It may sound simple, Musk said, but people rarely do it.