How do I make clouds?

[palistov]

Try using ps_area_fog_xlarge and/or ps_fog_sky. The area fog looks good as ground fog but putting some up higher in the map could pass for some cloud cover. The sky fog is a flat moving level of fog. It's only visible from the bottom though so don't panic if you can't see it from the top, just look at it from below

On another note: Fog areas are more of a global thing, they look pretty awful if you're looking outside-in. Don't try to use them for clouds :S