Cut your swag fabric twice the height of the window plus the width of the window. Turn your ends under 1/4 inch and iron. Turn the fold under 1/4 inch and hem.
Place your swag fabric on the work table or floor. Accordion-fold the fabric in 4-inch-wide pleats. Measure to find the center of the fabric. Insert a large safety pin through the pleats on both sides of the center point. Measure the width of one window section and add 2 inches. Measure away from your center point safety pins. Insert two safety pins on each side of the fabric pleats to hold them together. Repeat for the other side.
Cut three lengths of 2-inch-wide grosgrain ribbon 24 inches long. Locate the center of the curtain rod and align the pleated fabric with the center of the rod. Temporarily hook the swag fabric over each side of the rod, using the side safety pins as a guide.
Tie a ribbon around the center point and around each side safety pin location and unhook the fabric. Adjust the drape between the ribbons. This type of swag-hanging technique is used for fabrics printed on one side where the face of the fabric needs to face the room. When the drape is attractive, attach the pins to the back side of the ribbon so they're not visible from the front. Repeat for each ribbon.