Includes: Channel Mixer, High Pass Sharpen
Suggestions: Blues and turquoises=major saturation, be careful with blacks and the exclusion layer because the color could turn out pink. Pictures with bright red turn out pretty well too :]
Examples under the cut: More Lady Gaga
Step One: Crop your image to 100x100, sharpen if needed, etc.
Step Two: Duplicate your base layer, Adjust->Sharpness->High Pass Sharpen
Blend Mode: Hard Light
This step is optional. It intensifies the image a bit more, you can mess with the settings, duplicating the high pass sharpened layer looks good as well.
Step Three: Go to Layers->New Adjustment Layer->Channel Mixer, Normal 100%
112, 12, -19, 0
(112:red, 12:green, -19:blue, 0:constant)
6, 89, 15, -10
(5:red, 89:green, 15:blue, -10:constant)
0, 0, 89, 15
(0:red, 0:green, 89:blue, 15:constant)
Step Four: Go to Layers->New Adjustment Layer->Hue/Saturation/Lightness, Normal 100%
Master and Magentas: 0, 0, 0
Use settings that work with your picture, just make sure that the colors pop.
Step Five: Create a new raster layer & flood fill it with #bc9728, Multiply 20%
Step Six: Create a new raster layer & flood fill it with #cb2458, Exclusion 15%
[with high pass sharpen] [without high pass sharpen]
I'd love to see your results :]