We’re going to make an icon like this:

1. Open an image, select the part you want to use (I usually use the rectangular marquee tool holding down the shift key on the keyboard to have a perfect square), copy it (ctrl c), open a new document (ctrl n then click ok), paste it (ctrl v), resize it to 100x100px.

2. Add a New Fill Layer: Layer –> New Fill Layer –> Solid Color… write ffe0fa in the color palette; set this layer to mode: Soft Light;

3. Add a New Adjustement Layer: Layer –> New Adjustement Layer –> Hue/Saturation… with these parameters:
Master:: Hue: +33, Saturation: -22, Lightness: 0;

4. Add a New Adjustement Layer: Layer –> New Adjustement Layer –> Color Balance… with these parameters:
Midtones:: Color Levels: -29, +11, -20 with Preserve Luminosity checked;

5. Add a New Fill Layer: Layer –> New Fill Layer –> Solid Color… write e3fbff in the color palette; set this layer to mode: Soft Light;

6. Copy your base, drag it above all the layers and set this layer to mode: Soft Light;

7. Add a New Adjustement Layer: Layer –> New Adjustement Layer –> Levels… with these parameters:
Channel: RGB; Input Levels: 0 0.73 255; Output Levels: 0 255;

8. Add a New Fill Layer: Layer –> New Fill Layer –> Solid Color… write f9ffeb in the color palette; set this layer to mode: Soft Light, Opacity: 72%;

9. Add a New Adjustement Layer: Layer –> New Adjustement Layer –> Selective Color… with these parameters:
Neutrals: Cyan: +36, Magenta: +25, Yellow: -11, Black: +19;

10. Add a New Adjustement Layer: Layer –> New Adjustement Layer –> Color Balance… with these parameters:
Midtones:: Color Levels: +27, +21, +13 with Preserve Luminosity checked;

11. Add a New Fill Layer: Layer –> New Fill Layer –> Solid Color… write 00005a in the color palette; set this layer to mode: Exclusion, Opacity: 50%;

12. Add a New Fill Layer: Layer –> New Fill Layer –> Solid Color… write ffecfd in the color palette; set this layer to mode: Soft Light;

13. Add a New Fill Layer: Layer –> New Fill Layer –> Solid Color… write ffe9e9 in the color palette; set this layer to mode: Overlay, Opacity: 14%;

13. Copy your base, drag it above all the layers and set this layer to mode: Soft Light;

And you’re done!

Other Exemples with this technique which can be found in my Avatar page