Here's what I used:
5 1/2 ft. of light-weight gauze fabric (it was on sale for around $2/yard)
Curtain rod w/ rings (the kind that clip)
Here's what I did:
Measure the length of your window from the rod to the floor & cut the fabric to that length to create panel #1.
Using your clips, hang panel #1 over one half of your window.
Now, clip the remaining fabric (panel #2) to the other side of window, overlapping them in the middle by using one clip for both panels (btw- panel #2 should be longer than the first... you don't want them equal sizes).
Now just gather-up the bottom of the long panel and swag it over to the opposite side of the window (this is the side of panel #1).
So easy, right?!