I sent these pics to Lauren a while ago, when she was wondering what to do with a window in her new digs. (Hey, what did you do, Lauren?) They were still on my computer, so I thought I'd share. This is my downstairs bathroom and this window is right next to the toilet, so you can understand the need for utmost privacy here. In my humble opinion, this is magic with lengths of fabric and tension rods.
The white-on-white panel at the bottom of the window has a casing at top and bottom and it's held inside the window frame with two tension rods. I have made similar panels in lace to use where I didn't need quite so much privacy and, in that case, have often topped them with valances.
The panel at the top is much longer than it needs to be and has an extra casing in the middle, as well as a large ruffle at the top. I love how this looks -- it's dressy, but not too formal. But it can be formal, depending on the fabric -- or not. The sun has taken its toll on these, especially the top, so they're going to have to be re-done soon.
The real beauty of these, especially for someone just starting out or renting, is that they can be made for next to nothing. The "fit" is not crucial, so they can often be used in other rooms, other places; and compared to many other window treatments, they use a minimum of fabric. I have cut down larger curtain panels, sheets and other fabric that I've found at rummage sales or thrift shops. The biggest expense might be the tension rods, but they're not a bad investment, either!