Make your outdoor portraits pop with flash
By moving into the shade you avoid that stark direct sun hitting your subject, blowing out details and enhancing flaws. While we loose the heavy contrast we also can gain a certain amount of 'flatness' to the photo. The reason is that in brightly lit days there are no real soft, diffused shadows. The transitions are sudden. You're either in direct sun or in shadow. No in between. This is where off camera flash can be of help.
This image of my model, Christine, was taken outdoors on a bright sunny day. I had her stand on the shady side of a tree with the sun just peeking over her shoulder. As you can see it is a decent exposure. She is well lit and the little bit of light on the side of her face lights the edge of her face nicely. You can see her shoulder, where it catches the direct sun, how blown out the detail appears. While that detail is not important, it gives you a hint to the intensity of the light.
As I mentioned above, the sun was so bright that you were either in sun or in shade. There was no middle ground. You can clearly see the demarcation line between light and shadow on Christine's shoulder. The other thing you will notice is that her face is rather flatly lit. Aside from the rim light and some spectral light on the other side, her face is rather flat without any variation in light and shadows.
The best part of using fill flash like this is that it creates a nice spot of catch light on the eyes, making them look brighter and adding some life to the rather flat look of the photo above. While dragging around all this extra gear may not be appealing to some of you, you can not dismiss the added benefits of using this technique to make your portraits pop. Of course, if you have an assistant you can always make them do the lugging.