You will need:
Lace
Hot glue gun
Scissors
Iron
Curtain rod

Step 1: Cut Edges

Trim the tops and bottoms of the lace so they are straight.

Step 2: Fold Edges and Iron

Fold the edges evenly all the way across. I used the scissors as a guide so the next curtain would be exactly the same. Iron it down.

Step 3: Hot Glue

Glue the edge down in small sections, only a few inches at a time because the glue dries very quickly. IMPORTANT: Remember to pick up the lace as it dries so it does not stick to the surface your working on.

Step 4: Voila!

That's it. Slide it on the curtain rod, hang it up and your done. I chose to hot glue it because it's easier but you can definitely sew it instead to make it machine washable.