Ok here's me trying to be cute - I was really trying to get my eyes in this one because I had some fun with it. I read somewhere that bright eyeliner was coming in style and I always really enjoyed the white on the eyes as a bit of a brightener. So, what I did was outline my eyes with black eyeliner (very thin though and very close to the eye ball) then outline with the white. I like it because it REALLY makes you eyes stand out.
If I had a brighter color eye (say blue or green) then I would adore to do this with an eyeliner that matched my eye color - I think with brown it wouldn't work that well on my eyes.