I have been experimenting with sky textures lately, and tried to use 16bit textures for skydomes to have high quality skies without any compression artefacts showing up no matter the resolution or the exposure of the texture.
I also did some attempts to make stylised skies based on photo just by running a few photoshop scripts.
Some results :
I also did an "in engine" test with a low resolution 16bit texture projected on a dome to see how it looks.
I'm planning to use xtream Vue to generate the final spherical sky and then stylise it with photoshop.
I will probably use image based lighting to get more accurate ambient lighting. (based on following article : http://www.zspline.net/blog/2010/06/...ased-lighting/
As for volumetric clouds, I'm thinking of using speed tree modeler to generate sprites and slap a proper material which reacts to lighting accordingly.