Well theres an article about creating. Its Cesarsuki article go here:
http://my.mmosite.com/cesarsuki/Blog/Item/89b0ebf7a9dd644630291d3dfca091c3.html
and here:
http://my.mmosite.com/cesarsuki/Blog/Item/e87178cc72911e54dc1bccd54870871a.html

Ok, but I will tell about some secrets or glitches. On start I tell about simple sky. Sometimes is a point of the game, sometimes just we like him and admire or sometimes just dont look at it and enjoy game. I want to say that your graphic cards is efect of that beautiful moving sky. Look at this. Its warrock on law details:


Sky is a texture loaded on this structure:


and its a skydome strusture.
This is skyplane:


and skybox(like in Warrock):


Theres three modes. Most popular is skybox. He sorround world and you always will see sky. So even if  terrain will disapper, example long loading you will see DN(down). Usually its when you have too high ping and you can see DN(if game use skybox mode!).

In next article I say how HUDs, Heads-Up-Display(health, mana, armor etc), are looks like. And show you some glitches.