From the program description:
When is it real worldbuilding and when is it simply making the trees blue, the sky green, and calling coffee “glerp?” The panel looks at good and not so good examples of world building.
Blue trees -- I ought to try that some day. World-building needs local color, random little facts that have no particular significance in the story. And I am hard pressed to think of a way blue trees and green sky could be significant in the story. Trees, wild animals, flowers -- I think Diana Wynne Jones overdid it in
Which is where, perhaps, your "glerp" comes in. Tolkien, after all, admitted that pipeweed was unquestionably a form of tobacco. The name change was, no doubt, to make it homogeneous with hobbit culture. Then again, Tolkien was a linguistic genius such that he could construct worlds in language and make us believe them.
I find in world-building that the big issues are the ones that really make the world stand out. The magic system, or at least the appearance of system -- I find that a controlling metaphor for the magic works almost as well as real rule for making it hold togther, and shape the world about it. The society that forms from such a magic in such a world.
And social structure and all the rest -- many writers would benefit from reading widely in primary source not so much to gain info as to get their block knocked off and realize how wide the world has been.
part of bittercon