I don't have a bay window or a picture...but my sister has one and she took a decorative curtain rod and entwined a few window scarves (one solid and one printed) and draped them over the rod. It loooked great.
I'll see if I can find a picture similar to the look...
Ok, I can't find a similar look...but she basically entwined the 2 scarves very loosely and then draped them a few times over the rod (also very loosely)..and the excess just draped down on the ends. Very dramatic, yet simple.
(of course, this is if you do not need privacy...just something to finish the window)