Step 1:
Duplicate your base and set it to Screen.

Step 2:
Go to Layer<New Adjustment Layer< Selective Color.

Use these settings.

Reds:
-78
-22
-25
  7

Yellows:
-96
  1
  77
  66

Whites:
 100
-21
  19
   2

Neutrals:
  28
-12
-9
-8

Blacks:
  100
  100
  100
  100


Step 3: Duplicate your selective color layer and set it to screen.

Step 4: Duplicate your base and put it on top of both selective color layers. Set this layer to Pin Light.

Step 5: I added a Brightness/Contrast layer. Layer<New Adjustment Layer<Brightness/Contrast.
I used:

Brightness: -22
Contrast: + 4

I added a layer mask to this layer and went over the area of grass and the area behind Elle.


That's pretty much it. You may have to make changes depending on your cap. 





Here's a couple of other icons I made using these settings.

  

This is my first tutorial. I hope it wasn't too confusing. =]