Exposure

Bracketing - If you are taking a photograph and you have the time (like say, 30 extra seconds), "bracketing" your exposures is always a good idea. Many digital cameras have a bracketing mode that will take 3 pictures. The first will be deliberately "underexposed" (dark), the second will be the camera's best guess, and the third "overexposed" (light). If the camera's best guess is off by a little, then the first or third shot will be the best!

Image Stabilization - Also known as Vibration Reduction or Anti-Shake, image stabilization (IS) works to reduce image bluriness caused by movement. This feature is more common in cameras or lenses with large telephoto zooms. With IS turned on, photos taken in low light, and zoomed photos taken without a tripod will look noticeably better. For the technically inclined, that's "2 to 3 stops better". If low light or long zoom pictures are what you take often, look for this feature.

Sand and Snow - Bright conditions call for action!  If your camera is left in Auto mode, photos taken in these conditions tend to be underexposed, which means your subject will look too dark.  If your camera has a "Snow" or "Beach" mode, by all means use it!  Some cameras also have a spot metering mode, which will check the light only on your subject and ignore the background.

Outdoor Flash -  There is a secret you should know.  The best tip for taking portraits of people in the sun is to use your flash!  If you are 15 feet or closer to your subject, be sure to use your flash.  It will fill in the shadowy areas of people's faces.  If your flash doesn't want to turn on, force it on.  You may need to be in a mode other than "Auto" to force your flash on.