Creating a foggy scene

Start by opening an image of your choice. Duplicate the layer to secure the original image.

From image menu select adjustments>>auto contrast. (This step is optional if you want to adjust contrast in your image).

From layer menu select distort>>diffuse glow.
Use settings as per your image.

Change the color mode to pin light to control the area of fog.

It's quite easy to create a foggy scene using this technique. Also can be used to create a dreamy kind of scene.

 

Just make sure your source image has some highlight areas. Diffuse glow works best with light areas of the image.