I took this picture in Program mode with normal settings. I think it's cute, but there is a problem. When zoomed in, you can see this:
See those discolored flat patches? One below her left eye and one on the nose. We don't want those "blown out" pixels - particularly in an important part of the picture like the subject's face. They are a result of over-exposure. To fix this, I used the exposure compensation function. I simply dialed the exposure compensation to -.3 and tried again. I got this:
Not quite the same smile unfortunately, but better exposure. Compare the two close-ups so you will be able to recognize when to use exposure compensation too.