Portraits can be tricky. Too sunny and you'll have harsh shadows and lots of squinting. Too cloudy and the image can be a bit gray--but your expressions will look natural and terrific.
There are two good ways to add a little "pop" to an outdoor portrait. First, you can use a flash for fill. Second you can use reflectors.
For this sunny-day portrait, we avoided squinting by positioning our subjects so the sun was behind them. This allowed the sun to work as a rim light, adding highlights to the hair and shoulders. This also separated the subject from the background. However, without a reflector, the faces would be too dark--almost silhouettes. Add the reflector and you get beautiful lighting, making the sun do double-duty. We used a gold foil for our reflector to add warmth to the skin tones.
By using a telephoto lens and a special filter ("neutral density" for you technical types) to limit the amount of light that reaches the camera sensor, we're able to create a creamy-smooth out-of-focus background, drawing more attention to the subject.