I bought a simple room-darkening curtain panel at Walmart for $7 and a couple of spools of ribbon for $4. I wanted the length of my curtains to be 18". The middle curtain is 54"x 18" and the smaller curtains are 23"x 18". I added 2" to the length so I could fold over the hem.
I read on a valance tutorial for this type of curtain to make the ribbon 2/3 the length of the curtain. I hot-glued the ribbon into a loop and attached a bow to the seam. Loop the ribbon onto the curtain and hang it up.
My middle window is pretty wide so I put three ribbons on it.
And here's a picture of the one from the store. Not bad right???