Cut two pieces of fabric to measure 36 inches wide, 76 inches long. Select one of the fabrics to be heavier or thicker than the other so that one layer of the finished curtain is more sheer.
Lay both pieces of fabric onto a flat surface, with the right sides facing down, and fold the edges of each piece over by 1/4 inch. Fold the edges over again by an additional 1/4 inch. Pin around the edges using straight pins.
Sew around the pinned edges using a sewing needle and thread. Make the stitches as close together as you can to ensure that the stitching is durable. Cut off any excess thread with scissors.
Place the two layers together with the back sides facing the same way, and line up the edges.
Pin along the top edge with straight pins, then sew along the top edge with a sewing needle and thread. Cut off any excess thread with scissors.
Fold over the sewn top edge by 4 inches, folding it towards the back of the double-layered curtain.
Pin and sew the folded edge to create a casing.
Slide a curtain rod through the casing and trim off any excess thread before hanging up the curtain.