(MONEY Magazine) – Susan Byrne, 56, founder and CEO of Westwood Holdings Group in Dallas, sees two elements to her success (apart from her impressive long-term returns). First, she runs scared: "I never feel I've ever done the best job that I can do for customers. I always worry about them." Second, she's not afraid to be out of step with the herd. Byrne's company runs $4 billion, mostly for institutional clients. Her investing philosophy is hard-core value: She likes undervalued companies with lots of free cash flow. Period. That means hanging tough when those companies are out of favor. "Money management is about preparation and courage, not being popular," says Byrne, who started in the business 33 years ago as a secretary. "If that's difficult for you, then maybe this is not the right business for you. You have to have the courage to hang in there." --P.C.