We are going to go from this to this:
Using PS 7.0, medium (?) level of difficulty (uses Selective Color), may not be transferrable.
01. Crop the image you want to use to 100x100.
02. Duplicate the base. Then apply a Gaussian Blur filter (Filter > Blur > Gaussian Blur), set it to 2.0px. Set the layer to Vivid light, 50% opacity.
03. Add a new layer and fill with #DF98E2, setting the layer to Soft light, 100%.
04. Add a new layer and fill with #100534, setting this layer to Exclusion, 100%
05. Add a new Selective Color adjustment layer (Layer > Adjustment Layer > Selective Color). Apply the following settings:
Reds: -51, 32, -27, 38
Yellows: 72, -69, -55, -79
Blues: -100, 100, -86, -34
Magentas: -100, 100, -100, -73
Whites: -44, 0, 0, -100
06. Next, add a new Color Balance adjustment layer (Layer > Adjustment Layer > Color Balance) and use these settings:
Midtones: 58, -53, -100
07. Duplicate the base, drag to the top of the layer palette. Desaturate (Image > Adjustments > Desaturate) and set as Colour Burn, 20%.
08. Apply this texture (from immoral), and set it to Linear Burn, 50%. Then with the Eraser, delete the texture from around the areas that you don't want to have affected by the texture. In this case, it's Ayu's face and body.
09. Apply this texture (from cdg), and set it to Darken, 50%. Again, erase the areas that you do not wish to have affected by this texture.
It looks good so far, ne? ^_~
10. Next, we'll add some brushes to the icon. First apply this brush (from Ningengirai), set to Screen, 100%.
11. And this brush (also from Ningengirai), and set to Soft Light, 100%.
12. Now we can add borders. I applied a three pixel wide white border to the outside of the icon. Then set the color of the paintbucket to #BCBCBC, and applied a one pixel wide border on the inside of the white border.
And it's finished! :D
Optionally, you can add text to it, but I've been getting into textless icons at the current time, so we'll leave it like that. Remember to comment to let me know what you think of this tutorial, and I'd love to see your creations using it as well. ^^