The curtains in the living room were held up with clothespins for a while, but I wanted something slightly less transient, without spending any money.
I found that the color of the linen yarn (which is more like string, and difficult to find uses for) that my mother-in-law gave me was compatible with the curtain colors, so I crocheted a set of tabs, to be sewn to the curtains. I only have one crochet hook at the moment, which is a little on the large side, so the tabs are open and lacy.
When it came time to sew them to the curtains, I found the curtain hems difficult to stitch through by hand, and I didn't want to machine stitch, because someday I am going to move to a different house with different windows. So I used safety pins to attach the tabs, instead, from the back. (My grandmother gave me a little box of safety pins when I went off to college, and I still have it.)
With the curtains hung, the two panels are a few inches short of covering the complete width of the window. I had two extra tabs, from miscounting while producing them, so I used one of them to hang up the other in the space in the middle, as sort of a pendant. It still needed a little something, but I found a hoop earring on the sidewalk, so I added that.