How do you make your skyboxes?
I’ve googled around to find a few skybox editors, but before buying something random I was hoping for some recommendations. Or maybe tricks to just draw them by hand or generate them.
Are there other major formats of skyboxes other than this 6-image configuration?
Well, in the past I have created my own skyboxes - but it does depend on what you are after.
Spacescape - views of the universe. Example I created here . Works with Windows 7 and XP though for some weird reason maximum image size seems to be 2048x2048 with Windows 7 but 4096x4096 with XP 
Bryce3D - terrains . Kind of old software (32 bit) but can produce skyboxes. An example I created for a demo of instances of trees and rocks. - go to the terrain edge to see through the fog but don’t fall of the edge 
A tutorial here Still available from Daz 3D for $20, I believe, although there maybe ways of getting it for free.
Not sure if that helps.
cheers, gryff 
Good options, thank you everyone.
