Temperament is critical. There are people who are happiest working on their own. And there are people who would miss working with others in an office. You must have the temperament to thrive in whatever work style you pursue. Before you take an assignment, make sure you have the resources to succeed at it.
Pricing is a very intuitive, very personal thing.
Many people, in trying to get pricing right, overcomplicate it. Make your first buck. People may laugh at you because you charge so little. Well, you're in the game now, and that's how you get in the game.