Making fog

[04zx3]

I would like to know how to make fog on some photos.

thanks

[PyroTechniques]

Try adding Clouds on a new layer with white as your primary color and a fully transparent color (alpha = 0) as your secondary color. Erase whatever parts you don't want, and add some Transparency gradients (to make those the little thingy next to the gradient selections looks like this: :AlphaChannel:) to make them fade better.