I tried my best to recover the psd but to no avail. In turn, I attempted to recreate it with relative success...anyway, here it is:

step 1 I always like to start out with a blank 100x100 layer set to "transparent" because it allows for more flexibility as far as the scale goes but you can prep your image however you like. I chose an x-files screencap and used the "place" application to paste it onto the background.

step 2 duplicate your base 3 times, setting the top one to screen 9% (this image didn't require too much brightening so i left the screen layer at a low percentage, for a darker image it may be necessary to have more than one screen layer)

step 3 set your middle layer to normal 7% and desaturate it ( you may need to raterize the layer first, in that case go to layer-raterize-layer)

step 4 create a selective coloring layer (layer-new adjustment layer-selective coloring), set to normal 100%

REDS
cyan: 100%
magenta: 0%
yellow: 100%
black: 0%

YELLOWS
cyan: -100%
magenta: 0%
yellow: 100%
black: 0%

NEUTRALS
cyan: -19%
magenta: 0%
yellow: 18%
black: 0%

step 5 create a new layer and fill it with #441b1b, set to exclusion 71%

step 6 create a new layer and fill it with #9b4f05, set to softlight 28%

step 7 i made the follow texture from an image used by chaoticfae , set to soft light 23%
 

step 8 use a soft brush eraser-opacity 70% to erase whatever parts are too dark (the floor in this case)

step 9 create a new layer and fill it with #c1d0a7, set to multiply 37%


Other icons made using similar technique:

  

Please comment with any questions :) Also, I would love to see what you come up with!