The clouds feel flat. Add some bump mapping or displacement so they can cast shadow on Earth. Second point is add some atmospheric glow to the edge so it feels like the atmosphere stretches out a tad beyond the flat surface.
This is really nice already!
that atmospheric glow would be nice. when adding shadows to the clouds you could add more than one layer of clouds for variety and shadows of clouds on lower clouds.
I’m still trying to figure out how to do an atmospheric glow without it looking exaggerated and fake, but I think I’m getting closer to what you’re referring to. I’ve been experimenting with procedural textures for clouds and I haven’t quite found a balance that looks good yet. Thanks for all of the suggestions, they are all very helpful.