I'm going to attempt to do a semi-instructional here, so hopefully you can understand what is happening in these bad pictures.
We've lived in our apartment for over a year now. For most of that year, we used a big red duvet cover from Ikea nailed into the wall to keep the light out from the window behind our bed. Pretty classy.
Then I finally thought, "Hey, I could probably make that duvet cover into 2 panels and we could actually have curtains on both our bedroom windows!"
I realize this would be very easy for any sewer to figure out, but here's how I did it:
This cover is queen sized I think. It would probably work better with a king, but for our windows, this was just barely wide enough. Since I'm so exacting, I measured by folding it in half and holding it up to the window just to make sure. Then I ironed a crease down it length-wise so I would know where to cut.
When cutting down the crease, I would NOT recommend spreading it out over your lap like I did. Overcome your laziness to clear a spot on the floor large enough to lay it flat and then cut. As you can see, the other way is just plain awkward.
Now turn the panels inside out.
Line up the 2 layers of the cover on the side you just cut and pin down the length. You might be tempted to skip this, but since you are sewing down such a long length, the layers could get misaligned easily. Or maybe I'm just an amateur.
Sew from the bottom of the panel to the top. Leave about an inch and a half open at the top and backstitch to secure. (You might leave more or less space then this, depending on what you are hanging the curtain on. Or if you use those curtain tab things, you don't need to leave any space.)
Turn the whole thing right side out through the opening at the bottom where the duvet went on.
Now you could ladder stitch that bottom opening closed or something, but I just ironed it under. No one will examine the bottom of the curtains anyhoo.
Back at the small opening you left at the top, stitch the little seam allowance under so it doesn't peek out on the curtain rod.
On the other side of the top, make another little opening with your seam ripper and stitch the top of that one under as well. Repeat on the other panel and you are done!
Red in the bedroom is saucy, no?
I almost made our bed for this picture, but who wants to live a lie?
I think they will look better with some sort of tie. But putting up curtains is always so satisfying to me. It's the easiest way to make a room look more complete.