Cut a piece of fabric three times the width of the window, approximately 12 inches in length. You can cut it longer or shorter, depending on your window size and preference.
Measure in 20 inches from each end of the fabric piece and cut on the diagonal to remove the corners.
Cut the lining to match the curtain fabric and sew the lining to the outside fabric, right sides together. Leave one side open, turn the fabrics right side out and stitch shut the curtain.
Cut five pieces of curtain fabric 9 inches by 5 inches for the tabs. Fold the tabs in half lengthwise and sew the long edges together. Move the long seam to the center and press.
Fold the tabs in half, and pin the raw ends to the top of the valance, spacing them evenly.
Sew the tabs to the inside of the curtain. Back stitch at each tab to make sure it is stitched securely.
Slide the valance onto the curtain rod, adjusting it to make sure it is draped evenly.