One of the easiest and least expensive ways to update a room is to change the window treatments. Fish tail swags are easy to make, inexpensive and--depending on the fabric--can match any decor from the simplest country look to the most sophisticated modern style. You can even make swag without sewing; just use hemming tape to finish the edges. Panels with a fishtail valance are an option for style with privacy but, when privacy is not a concern, swag curtains alone are a lovely window treatment for adding warmth and texture to a room
Measure the width of your window. Decide how long you want the swag to be and measure from the curtain rod down to that point. Double that length, add it to your window width and add 12 inches. That final number is how many inches of fabric you need.
Lay the fabric flat, printed side up, and fold it in half from left to right, short side to short side, with the fold to your left. Measure in 10 inches from the lower right open corner toward the fold. Mark that point with a straight pin.
Use a yardstick and fabric pen to draw a diagonal line from the straight pin to the upper right corner. Cut along that line, through both layers of fabric.
Unfold the fabric--which is now shaped like a trapezoid--and lay it flat again, printed side down. Fold the edges into a 1/4-inch hem and iron them flat. Fold them another 1/4 inch and iron them flat again.
Stitch the edges or use hemming tape to hold them in place.
Lay the fabric flat again and accordian-fold it from the shortest edge of the trapezoid to the longest, with the folds parallel to the longest edge. An illustration is provided in the Resources section for visual assistance.
Use the measuring tape to find the centre of the length and mark it at the front of the swag (the short side of the trapezoid) with a straight pin.
Measure the curtain rod to find the centre and mark it by tying on a small strip of fabric.
Line up the longest edge of the fabric with the wall behind the curtain rod, matching up the two centre marks at the front. Affix the fabric to the wall with a thumb tack, a little bit below the curtain rod to obscure the tack.
Gather the corners of the fabric at the end of the curtain rod and use T-pins to hold it in place, making sure that the fabric is loose enough to allow the centre part to make a nice arc hanging down over the curtain rod. Arrange the pleats. You can also secure the pleats with T-pins, hiding them in the folds.
Tuck the corners of your swag behind large finials at either end of the curtain rod for a more polished look.