Outdoor lighting is something that can always change. The sun is always moving, there are clouds, possibly rain...all of these things will affect your camera settings. To properly shoot outside, you'll need to arm yourself with reflectors and diffusion panels, items that will substitute for a lighting kit as you manipulate and bounce sunlight around (We talked about diffusion in this video). Anyway, properly lighting outside doesn't have to be a total pain, as you'll find out here.
Always know where the sun is. The instinct is to use the sun as your key light, which you shouldn't fight at all despite the fact that the sun will likely get in your subject's eyes. To reduce the amount of light going into said eyes, place a diffusion panel between the sun and your subject's face.
You can use reflectors/bounce boards to create back-lighting by bouncing the direct light off of their surfaces and onto the back of the subject. You can also use them to balance the shadows on your talent's face.
The basic reflector types you can buy come in gold, silver, or white. Use the white reflector when you want to create a more natural light. Gold and silver create a more intense look with the corresponding tint. This allows you to add some color temperature if you think it's needed.