Dr David Travis of Userfocus wrote a great article on what makes a great UX consultant. http://www.userfocus.co.uk/articles/what_makes_a_great_ux_consultant.html
It’s not just about technical competence, but about soft skills surrounding the process of creating and selling great UX.
Thinking about my practice as a UX designer this way removes the narrow thinking I have that it’s all about output, but it’s not. Like how we say in UX, it’s not the product, it’s the experience.