1) Use the magic wand tool to select the background. Delete it.
2) Create a new layer and drag it to the bottom. Paste in this texture:
The icon should now look like this:
3) Hold down the apple key (or the equivalent on a windows) and click the layer with the deleted background (the one you want outlined.) This should select only the character you want outlined.
4) With the character still selected, create a new layer. Drag it to the top.
Go to Edit --> Stroke. Stroke 4px on the outside.
Go to Filter --> Gaussian Blur. Blur 0.5 px.
5) The image looks very flat. Create a brightness/contrast adjustment layer. Set to:
6) It looks too dark now. Create a curves adjustment layer and set to:
RGB (1 point)
Red (1 point)
Blue (1 point)
Now the icon looks like this:
7) It could use some warming up, so I create a photo filter adjustment layer. Use the warming filter (81) at 25%. Preserve Luminosity.
Add some text and you're done!
You can find my tutorials and icons at my icon journal, michl87_icons