Eyes, sparkly, vibrant, alive eyes.  That is what I'm trying for.  Do I acheive it every time?  No way.  However as of late, I have been purposeful in trying to acheive catchlights in the eyes.  A couple of things that are needed:
(1) subject facing a light source but not directly in the light.
(2) precise focus on the eyes
(3) willing subject (harder than the first two)

Sometimes when the subject is in bright light or the light source is strong I have them sit with their eyes closed until I'm ready to take the photo and then I count to three and click.  Here are some of the catchlights I've acheived.  Click on the photo and then click to zoom in.  Sometimes I can get a great reflection of me in their eyes.
J'aime les lumiere dans les yeux.   Cliquez sur le photo et cliquez un fois plus de voir qu'est ce que c'est dans les yeux.  C'est important du personne tourne vers la lumiere mais n'est pas dans la lumiere.  C'est aussi necessaire de mettre l'accent sur les yeux et le personne est agreable du photo.