ayxieebz:

Well first off, this works really well on black & white pictures, so you might wanna use a gradient map to make it black & white, I used the colors #302624 and #ddd5cc, after flatten the image.

1.) Duplicate your base layer, Layer> Duplicate Layer. And then make a new layer on top of it, Layer> New> Layer.

2.) Make sure Layer 1 is selected, hold down ctrl+A, and then go to Edit> Fill or hold down shift+F5. Now fill it with any color you want, I used #8a8a24, now set your layer to Lighten and merge it with you base copy.

3.) Set your duplicated base layer to Darken, and then move it a little to the left. Now just flatten your picture.

And now your done, see that was easy right?! If you  want it to look like this, then just make another layer and follow step 2 again, but use a different color~

You can request a tutorial here, I hoped it helped!