Planets like these? http://www.cartographersguild.com/showthread.php?t=1657


Quote Originally Posted by Ascension View Post
I think many of the people here use something like Fractal Terrains or Wilbur because they up a full planet. I don't have either so I can't be sure but I am sure that those that do have them will chime in sooner or later. I, and a few others, use good ole Google Earth. We make up our own world then import it into G.E. There is a quasi-tutorial around here somewhere that shows exactly how.

It's in this thread:
http://www.cartographersguild.com/showthread.php?t=2607

Just read through the posts and further down (page 2) the Master RobA explains it. As far as making up your own world to import into G.E., well there's a ton of tutorials here to help get ya started.

If this is pertaining to some of those artwork pieces from a few months back, then they used Photoshop and/or GIMP in a more painterly style. There are tutorials on the web for making them.