The eyes are a huge part of a successful portrait (they don't call them the window to the soul for nothin'!) and one way we can make sure they really look their best is to make sure that they have catchlights.
WHAT ARE CATCHLIGHTS?
A catchlight is nothing more than light being reflected in the eyes of your subject - they are the white areas you can see in the eyes on the examples below. They help to make your subject look alive, and give depth and life to any portrait - without them the eyes look lifeless and empty. The good news is they are incredibly simple to achieve - it really is all about how you position your subject!
HOW TO POSITION YOUR SUBJECT TO GET CATCHLIGHTS
The easiest way to get catchlights is to simply ensure that your subject is facing into the light - if indoors, this would be toward the window or open door (tip - open doors give FABULOUS catchlights!)
If outdoors, either look for open shade (where your subject is in shade looking out onto the light) or on an overcast day, looking slightly up. If you are unsure, just look at your subject's eyes! You will see the light reflecting in the eyes as you look at them - if you can't see it, keep turning your subject until the light hits their eyes.
ANYTHING ELSE I SHOULD BE AWARE OF?
In an ideal world we would have the catchlights either at 10 o’clock or 2 o’clock on the subject's eye I must confess to not worrying too much about exact placement (If you are photographing children, you usually get a nanosecond to react - getting exact positions for catchlights aren't really going to cut it) but IF YOU CAN, avoid having the catchlights fall directly over the pupils. Just don't have your subject face the light straight on, rather angle them slightly from it, and you'll get get perfectly placed catchlights AND introduce some shadowing on their face that will give depth and dimension.
EDITING CAN REALLY MAKE THEM POP!
You can bring out catchlights even further in editing too! Boosting brightness, saturation and contrast can all help emphasis the twinkle in their eyes, but if you have done a good job in camera, you definitely won't need to do much here :)