Here is a basic lighting setup for outdoors portraiture images:
1. Set your camera to Manual Mode and underexpose the background for about 1
2. Use the sun as a backlight (if there is no sun available, place a speedlight on a tripod and point it on the subject’s hair)
3. Set up a speedlight in a softbox (for smooth lighting) and place it at 45 degrees angle high and above from your subject (if you don’t have a softbox you can use an umbrella or a diffuser)
4. Control your speedlight(s) via the pop-up flash of your camera (if you don’t have a pop-up flash you can use the SU800 IR transmitter, another speedlight, pocket wizards, or cords)
The above image was taken to a local park by using the sun, an SB900 attached on a softbox and an SU800 on a D3s.