This quick little tip will give you an instant colour boost for the eyes of your subjects, whether it's people, or pets. It's fairly simple, and much quicker to do than it is to read the tutorial.
You copy just the eyes to a new layer - the colour part of the eye, not the entire eye. To that new layer, apply a cooling photo filter, and instant wow. Especially if you've got someone with great eyes to begin with.
Other instructions included with the tutorial are using the Nasa image "Big Blue Marble" in the eye, or adding a star to the highlight.
A couple of useful links: Nasa's image library (Nix: Nasa Image XChange) is offered free for use, at least most of them. You need to double check before you download, because I have run across the odd one that is copyright protected by the artists, but most of the space photos are listed as free for use.
Just keep in mind - though Nasa has an extremely liberal usage policy, it's not nice to take a free image like the Big Blue Marble, and try to sell it on a stock site. I've seen this happen, and frankly, any "artist" who does that is no artist at all.
That's not to say you can't sell an image that you have created with this image - there are lots of images that make use of the earth photo from Nasa, but almost all the good ones are those that have made the marble only part of the image - an element in the finished piece.
And a place to download free star brushes, in case you don't have the right kind. Brusheezy has lots of brushes. This particular star set is by Jen-ni.
Download the full tutorial including step-by-step images HERE.
PLEASE NOTE: THE PDF PASSWORD IS notheft