Attached Link: Arcania

Just wanted to show some fog in the lower parts of the city, but it didn't come out well. I used volumetric clouds in a box and a HDRI sky. Any hints on how to get more fluffy clouds?

I also used volumetrics for the trail of the sky vehicle. Didn't get as fluffy as I expected. Used some additional postwork. Any hint on that?

Any tutorial on how to make good clouds?

Thanks for your attention.