If you must shoot under such conditions turn your subject so that the light comes from a 45 degree or even 90 degrees and then use a fill flash for the shadows. Move the subject into the shade. Open Shade Open shade is a photographer's best friend. Move your subjects into a bright shady spot and use your flash if necessary. This avoids the problems of harsh sunlight.
Colors are brighter and there is much less glare.
Under trees, watch out for the dappling light spots caused by sun coming through the leaves. Use fill flash and reposition your subjects. Use Reflectors A mirror, a small piece of cardboard wrapped with foil, a white wall or any other reflective surface will reflect light back onto your subject and open up the shadows. Place the reflective surface out of the image area but close enough to the subject to bounce light into the darker shadows. I'm in the process of buying my first SLR camera, and I have found the tips on your page to be extremely helpful.