Exposure: When I need to consider the exposure?

Let�s me say that all the time you are carrying the camera :) because of most of the time, you can just take the shot and press the shutter release. However, non forget to adjust the exposure only when you need it, Use this decision process:

Do I need to adjust the depth of field�If YES, make the comparing the sharp of background is sharper or lower than foreground then adjust your aperture/shutter or use the aperture priority mode.

The camera is designed for this scene you want to take or not? You can apply exposure to be under or over the scene.

Use the spot meter or lock the exposure for that part of the picture you want to lighting specific part and recompile the scene.

How about the shutter speed I want to have the movement in my picture ? If YES, adjust the aperture/shutter, or instead use the priority of shutter.

Besides,

If it is so dark such as with the sun behind? Overexpose the scene.
If it is so bright such as on fresh, bright snow? Try underexposing.