Here’s a post processing technique to create a stylised blue cast to your image, along with additional work to create depth and a slight glow to skin highlight (creating a “dreamy” effect on skin tones). Here’s a preview of the type of effect this technique will achieve (original lower left diagonal, post processing upper right):
This is the starter image (see the previous tutorial on the skin retouching technique used):
1) Start by creating a new empty layer then select Edit > Fill and click the Use drop down box and select 50% Grey. Click OK then set the layer blending mode to be Overlay. Next, with the brush tool, paint with black on the fill layer, at a very low opacity (1-2%) where you would like to deepen the shadows. Repeat for highlights using a white brush, again at low opacity. This is your dodge and burn layer. If the effect is too much, you can reduce the opacity of the layer until you get a result you are happy with. The second image shows the layer in normal mode.
2) GIve the image a blue colour cast with a Curves adjustment layer. Select the Blue channel, and rotate the line clockwise by dragging the bottom end of the line up, and the top of the line down:
3) De-saturate the image with a Hue/Saturation adjustment layer. Set the saturation level to ~-30 and set the layer blending mode to be colour
4) The next step with create more depth to the image by enhancing highlights and increasing shadows. Create a new blank layer and make sure you have white set as you foreground colour. Next go to Select > Colour Range and move the Fuzziness slider until just the main highlights are visible:
Click OK then use the fill tool to fill the selection with white. Next apply a gaussian blur (Filter > Blur > Gaussian Blur) with a pixel radius of 5 to the layer. Repeat this step, but this time make sure that Black is selected as the foreground colour. Adjust the Fuzziness to show just the deep shadows (the image will be inverted, so the shadows appear white), click OK and fill the selection with Black.
Adjust the opacity of these layers if the effect is too strong
5) Use layer masks to increase/decrease the effect of the various adjustment layers. This shows some of the masks I applied to bring back some of the colour in the main subject
Here’s a comparison of the stating image compare to the final result (the image was finished off with a slight exposure boost to the eyes and a subtle vignette)