Requested by danielachan.
First, get your base ready. Mine is of Miss Mosh and is made by girlcalledxkill. You can sharpen your base, duplicate it, etc., etc., but for this tutorial, I didn't do anything to my base. I just left it alone. You might want to experiment with it, depending on the type of lighting you have for the image you pick. Please note: this tutorial works best with images that have some red and/or blue that you want to pop. In this case, it's the eyes and lips. Although, feel free to test this out with images that don't necessarily have blue/red you want to stand out!
First, we're going to add a Curves layer.
RGB, Input: 115, Output: 136
Blue, Input: 121, Output: 139
For this layer, I wanted to brighten it up a little bit and add some blue to the image. The image turned out a little too blue, though, and the lips didn't fit in.
Next I made a Selective Color layer.
Reds: -100, +70, +100, -30
Yellows: 0, 0, +30, 0
Whites: 0, 0, 0, -60
Neutrals: +50, 0, 0, 0
Wow, that was a switch! The whites of her hair increased, the lips fit in more, and the eyes are a gorgeous blue! Plus her skin looks much smoother and nicer now.
Make a new color fill. Fill it with #3a2f33 and set it to Lighten 40%.
I wanted the blacks (even though there are little in this image) to have a little gray-er effect. If your image has more black and it looks weird, feel free to make the percent lower, or the other way around.
The saturation (mostly red) wasn't high enough, so I made a new Hue/Saturation layer.
Now the reds on my image are a little more upped and the yellow in the background looks brighter!
To darken my image a tad, I added a new fill layer with #e5e6ed. I set it to Multiply 50%.
And you're done!
Here is the .psd, if you're interested.
Base credit, 1/2/3.