You find and use open shade, or you set up an overhead diffuser to make your own open shade. You can use reflectors or strobed light for fill/accent. Avoid dappled sunlight, it's about the worst light you can use.
With open shade the sky becomes your main light. You put your subject somewhat close to the sunlight/shade line. How close depends on what the sunlit ground is like, it's color and reflectivity.
With all blue sky you have to be careful your subject doesn't get a blue castbecuase they wer to close to the sun/shadow line. You also have to mindful of green color casts from tree leaves/grass, brown color casts from dirt, and unwanted light bouncing up off of concrete.
I liked using an overhead diffuser. I would then use strobes gelled to tungsten (CTO) for the exposure on the subject. and set the camera white balance to tungsten. That gives all the background ambient light a nice, light, cool blue cast that really compliments people's facial skin tone.