I suspect the ‘tricks’ I employed here would not work well with other non-cloud things in the scene. But I haven’t tried either…
For the volume shaders, I went with two Volume Scatter nodes and a Volume absorption node, all added together. The first scatter had a high positive anisotropy, while the second had a high negative anisotropy. Splitting it into three volume nodes, rather than a single principled node, allowed for each of these to be controlled wrt color and density. Unlike cycles, the clouds will not fill in with color from the sky (at least they didn’t for me!), so this had to be faked by adjusting the colors by hand.
For the lighting, I used three sun lamps, each with a different direction, color, and strength. Additionally, there are two point lights acting as the sun at the bottom-center of the image. One more yellow, one more orange.
As for UV maps, I avoid them whenever possible! Partly because I am procedurally inclined, and partly because I haven’t yet learned to work with them properly. If the built-in unwrapping doesn’t work well, I don’t try to take it any farther. Some day I’ll buckle down and make myself learn the art of UV magic, but not today :).
Hopefully some of that is helpful for you. The machine I’m primarily using right now really struggles with eevee, but I have another with a decent video card. So I may try to make a scene with buildings and such to see about lighting clouds when there are other elements to consider.
Also, if you haven’t seen it, @Pixelshatter has a cloud node available for download here, and it is supposed to work well with eevee now. These clouds here don’t use it, but I’ve played with it a little and I think it could be quite useful.