It's tough to get good light that's also natural light. Evenings and mornings work better since the light it more from the side, but generally you have a choice between cloudy/shady -> too diffuse to be interesting and direct sunlight -> too intense.
Either way, experiment with using reflective or white surfaced objects to bounce light into shadows (to soften the look up when it's too intense), or to intensify the light (when it's too diffuse). Anything will work. A guy in a white shirt standing just out of frame will have a STARTLING effect, once you start looking closely.