To hang swag curtains, gather the fabric where the curtain begins to drape and attach it to one end of the curtain rod. Then, having allowed the desired amount of fabric to hang in an arc below the rod, drape the other end of the fabric on the other end of the rod. Achieve different effects by adding one or more loops to the swag.
Drapery manufacturers generally make swag curtains from long, flowing pieces of sheer, lightweight, well-draping fabric. Basic swag curtains require nothing more than draping the fabric in a variety of ways, but more complicated designs may employ multiple drapings and gatherings.
Swag curtains can be used as the main window treatment or can be paired with other fabrics or curtains to create different aesthetic effects. Some prefer hanging curtains so that the lengths of fabric at the ends of the curtain are symmetrical, which involves finding the center of the curtain then distributing the fabric evenly on the drapery rod.
SFGate.com recommends tying knots in the fabric where the curtain meets the curtain rod to prevent the curtain from sliding out of place. You can also use hardware or speciality swag curtain systems to permanently fix the curtains in place.