I'm hanging a drapery rod today and am trying to decide whether I want the rod level with respect to the ceiling or just level. I did some googling to help me with my decision and found this gem from Popular Science, circa 1970. It's says:
"Sure, she knows fabric. But hardware? The only way you can be sure of getting the right hardware -- hardware that will fit, install easily, and need no attention once it's on wall -- is to handle that end of the job yourself."