Sociability. Reliability. Ability to take criticism. Stress resistance. Diligence. Productivity. Ability to take criticism. A successful freelancer doesn't get emotional. He understands that he is not perfect, and knows how to accept feedback. He is also okay with his mistakes and adequately responds to requests to make changes to the project. Continuous professional development. A successful freelancer is always in the position: “I know I don’t know anything.” But this position does not make him feel incompetent, but encourages him to constantly learn. A freelancer's skills are his main tool.