How to focus on the eyes with a DSLR?

I have a Nikon DSLR, but I'm pretty sure that settings are similar to other DSLRs like Canon's, or Sony's, or Pentax'.

When taking portraits, or people, you should always focus your camera on that person's eyes. But, how do you do this? Do I set my focus mode on "Single-point AF" and manually select the focus area on the eyes or just leave it at "Auto-area AF"?

How about my metering? Do I set it to Matrix, Center-Weighted, or Spot given that my subject is in the dead center and in a non-studio background?

Easiest way is to set to single-point AF, with AF lock, then set your focus point. Middle focusing point is fine, simply lock the focus on the eyes, then re-position before taking the shot. Metering depends what lighting equipment you're using. Center-weighted should be fine if you're shooting in natural light.

Set the auto focus points on the eyes, and lock the focus.

For me…

1) make sure the diopter is properly set. I have to adjust mine as to whether I have on glasses or using contacts.
2) metering is set on center weighted
3) manually focus. I rarely use AF unless I'm tracking a fast moving object
4) use a f/stop that will do at least a 6" DOF if at all possible

I always use the single focus spot locked in the middle position. I focus and recompose with focus lock.

I use either center weighted or spot metering, depending on what I'm shooting and how the lighting is.

Back in the day I could manually focus, too. But I now depend on the auto-focus because of my eyesight. I have found that AF is pretty accurate, and when it misses it was probably operator error!

Another thing to consider is your aperture and the resulting DoF. With wide apertures, sometimes one eye is in focus and the other is not. So be sure your DoF is matched to the job at hand.

Yes, single point AF. Auto-area focus will focus where the camera wants to, not where YOU want to. Auto-area focus is for amateurs. Don't use it for portraits. Set your focus so that it focuses in the center of the viewfinder. Place the center of your viewfinder on the subject's eyes, press the shutter button halfway down until it focuses. While STILL HOLDING the shutter button halfway down, re-compose and shoot. Be sure and not move forwards or backwards after you lock the focus or it'll be out of focus.

If you're not using studio lighting, how you meter it is up to you. I usually use center-weighted metering, then shoot one. I look at it on the camera, then I change to manual exposure and set the same aperture and shutter speed that you just shot. If you need to adjust the lighting, then you can change it as needed. Depending on the light, etc., you can change either the shutter speed or the aperture to get the exposure you want. I always shoot my first portrait shot on Aperture-priority because I typically want f/5.6 or f/8, depending on the subject and how shallow a depth of field I want. Then I change to manual and adjust the shutter speed accordingly.