When you are shooting portraits of people in front of you and behind you, use Aperture Priority, open wide aperture, center focus metering, and focus on a single point at a single time.

Shooting people in motion and wanting to show movement through blur effects, use shutter priority, slow shutter speed, multiple successive focusing or area successive focusing.

Take photos in a Japanese style with auto plus exposure compensation +1 stop, slight overexposure but not overflow, you can meter directly to the skin.

Photographing portraits of humanities subjects is not a very fixed model, more than 35mm small wide-angle or standard head, the exposure is controlled according to the actual situation, think of what to shoot.

2, backlight shooting:

The use of central focus metering or spot metering, skin metering. But may be the person photographed normal background will be overexposed.

You can also use the flash to fill the light on the front, but the overhead flash is easy to make the photo too flat. It's best to use an off-camera flash for sidelighting.

You can also divide the metering, according to the dynamic range to adjust the exposure parameters, now the dynamic range of the DSLR in the 7 stops or so, and later PS to pull the curve.