Ask most any photographer and they will tell you the worst time to shoot outdoors is mid-day. With the sun directly overhead the image is likely to either have deep shadows or blown highlights, not an appealing result for professional photos. Most often under these conditions, the subject is left with deep shadows in the eyes.
A great way to overcome this is to use a flash when shooting portraits in overhead direct sun. This will fill in the shadows and even out the exposure for a more appealing look. The only drawback is that direct flash often leaves the image with a snapshot like appearance since the additional light is coming straight from the camera.
The next step to improving the image even further is to move the flash off the camera and direct it to the subject at an angle. Not only will the shadows be filled in, but the angle of the light will help add dimension and a more appealing look.
On a recent engagement shoot with Jacqui and Roy, we were out during mid-day. I actually employed a couple of techniques to produce an appealing look. Many of the poses were within the shadow of the building or trees, which helped even out the amount of light and reduce the direct light falling on them. Since I am all about off-camera flash I also used that to enhance the photos.
In this first photo you can see how the image appears without any additional light. I adjusted the exposure to get a beautiful looking sky, but you can see Jacqui and Roy are completely within shadow with no detail.
In the next photo I added off camera lighting and fired my flash through a translucent umbrella to reduce and soften the shadows. What a dramatic difference.