How To : Great Digital SLR flash
Nobody likes it when their $1000 digital SLR shoots flash shots worthy of a $10 K-mart disposable camera. Step up your game with the technique below. Note - this works for both pop-up and external flash units.
Rather than using Program or Aperture Priority, set your camera to Manual. Dial in a nice setting like 1/60 and f/8. This forces the camera to use the flash output to determine your exposure. Next, select the center focus point. Aim your camera at your subject and be sure to lock focus and exposure onto your subject’s face. After you lock it down, you can always re-compose.
Fire away and check the shot. If you want more ambient light to balance out the flash, just extend your shutter time. If your flash is too weak, then open the aperture a stop or two.