I kind of just experimented so these aren't the exact steps but they're in the ballpark.

Basic steps…

-Convert to 16 bit color
-Make separate layers for luminosity and color
-Apply 100px High-Pass to luminosity layer
-Apply Levels to luminosity layer aiming for a dark high contrast look
-Apply subtle USM to luminosity layer then fade > darken. Repeat this a few times.
-Experiment with Hue/Saturation to the color layer until you get a look you like



More advanced steps…

-Make a copy of the eyes and put them on a separate layer on the top of the layer stack. You don’t want them as dark as the rest of the image.
-To really make your image “pop”: Make a copy of the luminosity layer. Blur 5px > Find Edges > Auto Levels > High Pass 5px > Auto Levels > Invert. Move layer to top of layer stack and set blending mode to overlay with an opacity of 50%
-Make a mask to darken the background.
-For some interesting color effects: Make a copy of the color layer. Solarize > Auto Levels. Move layer to top of layer stack and set blending mode to overlay with an opacity of 15% Experiment with Hue/Saturation until you get a look you like





http://images5.theimagehosting.com/layers.gif