When editing the eyes for beauty images, don't be tempted to give your model vampire eyes. In this cropped close up, I kept the colour of the iris and the eye whites natural by simply increasing contrast and brightness. There is nothing worse than seeing a portrait of a beautiful subject ruined by spooky over-saturated eyes.
In some circumstances, you may want to doge and burn the iris to add pop and contrast, but again don't overdo it.
As far as the eye whites go; Again, keep it simple. Don't remove all of the veins, and remember that the eye is spherical - there should be some shadow to show this. Don't over whiten the eye whites. If you have enough light on your subject, you shouldn't have to whiten the eyes at all. In some cases it's desirable to keep them dark.
Adding a subtle soft dark edge to the iris can give a nice effect.