So window treatments enough can be costly, but when you're dressing a very large window, it gets even more expensive. Because usually the window treatments that are stock or ready-made are not apropos for these windows. So you can't just go out to a store and buy something. You have to usually get something custom-made.
So you pick your fabric and you make the custom lengths to it. That's all fine and good, but what do you do when you really don't want to spend a ton of money or you don't want to wait a really long time for the window treatments? Well, there are a couple of things you can do and also, some solutions.
One is what's called a window scarf. A window scarf is basically a long, scarf of fabric, like you would tie around your neck. But it spans like 100 inches up, until 200-300 inches. Basically, you put a rod across the whole upper window and then you'd sashay literally, the scarf across it. So that not only it adds some texture. It adds some context, but it dresses up the window without leaving it bare.
Then if you want to block out the sun or you're worried about privacy, you can do a hard shade. Which is basically like a blind or a soft blind, on the inside of the window that you can pull up or down or even open or close. Those you can get custom-made, but they're less expensive sometimes than doing custom long window treatment drapes.
If you have to go custom, then really the world is your oyster and you can pick fabric and color, and material. Just remember if you do panels, let them hit the floor. They shouldn't be high waters, remember those pants when you were younger. You don't want high waters on your window treatments. So you have scarfs. You have panels and then you have your hard treatments. Either way, you can't really go wrong when decorating a large window.