We'll be going from this 
to this 
1. We start with this base:
2. Duplicate the base once and set it to soft light opacity 100%
RESULT:
3. New adjustment layer-->gradient map-->black&white
RESULT:
4. Past this texture:
on top of everything and set it to lighten opacity 90% fill 70%
RESULT:
5. Past this texture:
on top of everything and set it to multiply opacity 100% fill 100%
RESULT:
6. Past this texture:
on top of everything and set it to multiply opacity 100% fill 100%
RESULT:
7. Past this texture:
on top of everything and set it to lighten opacity 100% fill 100%
RESULT:
8. Add some text or brush or whatever and you're done
RESULT:
Other icons made with this tutorial:
to this 1. We start with this base:
2. Duplicate the base once and set it to soft light opacity 100%
RESULT:
3. New adjustment layer-->gradient map-->black&white
RESULT:
4. Past this texture:
on top of everything and set it to lighten opacity 90% fill 70%RESULT:
5. Past this texture:
on top of everything and set it to multiply opacity 100% fill 100%RESULT:
6. Past this texture:
on top of everything and set it to multiply opacity 100% fill 100%RESULT:
7. Past this texture:
on top of everything and set it to lighten opacity 100% fill 100%RESULT:
8. Add some text or brush or whatever and you're done
RESULT:
Other icons made with this tutorial: