I'm liking the warm color pallete (maybe because it's cold as sh*t here!!) How did you make the near planet? with PS? i think it would help if you could get some more depth there, maybe shadows cast by the clouds on the terrain, mountain ranges, etc..... also (and this is just a random idea i had after viewing yours) it might be cool to give the gas giant rings, and have them eclipse the main star just a little, maybe casting some cool shadows on the near planet.
lol, yeah - gas giants can be easy to paint with a 3D look without te spherize filter. Usually I do a bit of both since I like to add extra details after spherizing or rendering one myself I like the bright, warm colours, and the whole thing has a classic feel
Well, they were made from a custom brush, which was basically lots of repetitions of difference clouds, then I used that to paint the gassy background for this then I applied that on to a clone brush and made what you see here