STEP 1: Using the Magic Wand tool I quickly blocked out a layer mask. After, I tweaked it with "Refine Edge" and a small round brush (on the mask layer).
STEP 2: Another stock image (same source) of a stormy sky was placed in another layer beneath the model.
STEP 3: A really great resource for finding brushes and other resources for Photoshop is a site called Brusheezy. Using some brushes I found there, I created another layer between my model and sky and laid in some brushwork in white drooping the opacity to 80%.
STEP 5: I duplicated the sky layer and moved it to the top at this point. Using Hue/Saturation, I adjust the color. After creating an accompanying mask, I used the Gradient tool (Black to Transparent) to fade the new sky layer.
STEP 6: Next I set the blending mode (new sky layer) to "Soft Light" at 100% opacity. Steps 5 and 6 combine for a nice subtle cohesion in color.
STEP 7: Using Nik Software's Color Efex Pro, I use "Film Efex: Modern" to achieve this grain effect which was a bit too strong.
STEP 8: When using Color Efex Pro, the filter effects are applied to a new layer combining all layers you have turned on. So leaving my working layers on. I set the new filtered layer to 40% opacity to achieve the final look I was after.
Hope you enjoyed the tutorial. It was fun to create. Let me know what you think of the final image. I think the hardest part is sometimes knowing when to stop :)