Scalloped edges give a feeling of movement to this valance, especially when it is tightly shirred. Cut a strip of fabric two to three times the width of the window by the desired depth, adding 1/2 inch for seam allowances on all sides. Cut lining to match. Pin pieces, right sides facing.
Divide the valance width (minus seam allowances) into an even number to determine the width of the scallops. Draw a scallop template on lightweight cardboard. Transfer the design to the lower edge of the valance. Mark the upper and lower edges of the rod pocket. Sew all edges, leaving an opening at the top for turning and at each side for the rod pocket. Trim excess fabric from scalloped edges and clip the curves and points. Turn the valance to the right side, press, and slipstitch the top opening closed. Topstitch between the marks to form the rod pocket. Pin wide double-fold bias tape to the upper edge of the valance and topstitch in place, turning under the raw edges. Pin bias tape to the scalloped edge, mitering the upper points. Topstitch. Shirr the valance on the rod.