First, we painted a couple of "candy cane" poles on the window to help "frame and contain" the design. Anna did one and I did one.
After painting, I screwed in the poles to the window frame. I already had all the strings ready so then it was just a matter of threading and anchoring them through the holes I had drilled in the pole.
The above is a cardinal made from felt scraps with twisty ties sewn to its wings to keep them "flying".
Anna with the finished masterpiece. Because the windows are dark, you can see it from pretty far away.