Colourising

Open the image that you want to work with and copy and paste it into a new document.

Now grab your Lasso tool with Feather at 1px and select an area to colour. Here I've started with her face because it is the most prominent area in the picture. Use the Shift and the Alt keys to add or delete from your selection. Zoom in to make sure you've selected all the details.

Next go to Image > Adjust > Color Balance. Use these settings:

Shadows : Cyan(+30) Magenta(0) Yellow(-20)

Mid tones : Cyan(+45) Magenta(-25) Yellow(-75)

Highlights : Cyan(-5) Magenta(-4) Yellow(-5)

I played around with the colours to get her tone; you can do the same if you don't like her shade here. Just remember that to make "skin" colour you need a mixture of yellow and red.

Okay, now for her eyes. Select the iris part (the colour part) and make sure to not select the pupil (the black part) or else that will change colour as well. We'll give her some nice warm brown eyes.

Shadows : Cyan(+5) Magenta(-70) Yellow(-100)

Mid tones : Cyan(-20) Magenta(-30) Yellow(-70)

Highlights : Cyan(-10) Magenta(-12) Yellow(-10)

Pretty cool, hum?

You can also give her green eyes...

Or blue...

And even some nice grey eyes. It's pretty much up to you! Experiment!

Do the same things over with the other parts of the image. Play around with the colours until you come up with something you like and voila! instant masterpiece! Notice that I added a peach tone to her lips. I also darkened her eyebrows and eyelashes with the Burn Tool on a low setting and just kept going over the same area until it was the darkness I wanted.