Use the brush to draw horizontal lines over the image. This will create even and not very realistic fog so we need to make it thicker in some places. Set the Opacity of the brush to something like 70% and make areas with more grey. Your image should now look something like the one bellow.
We have the fog overlay Photoshop effect, but the highlights look clipped. In the image used for this tutorial, the wedding dress turned into a white blob. In the steps below, you will learn how to fix this problem and restore detail to overexposed areas.
You could leave it at that (and I've seen photos of real fog that look just like this), but to give the image that extra bit of pizazz you can add some texture to the fog as follows:
Learn how to use Photoshop to add a dreamy fog effect to any photo. This Photoshop tutorial will teach you how to use several layers to create a realistic fog effect that appears thicker in the distance.
5. Staying in Layer Mask choose a brush with soft edges. Paint everything within edges you intend to be clear. It will remove the fog from this area and give your image the illusion of depth. In the example photo I cleared the front grass line. If the fog effect seems too strong, you can reduce Opacity of Hue/Saturation layer.
Taking photos in the fog usually results in an underexposed, low contrast image. In this tutorial, you will learn how to use the levels and brightness/contrast tool to remove the fog and restore the details and colours in the photograph.