Measure the length of the window. Select a skirt that could cover the window's length. Lay the skirt face up on a flat work surface. Smooth out any wrinkles.
Make two vertical cuts, one along the right side and one along the left side. Try to follow the seam lines if any are there. When finished, you should have two identical panels of fabric composed of the front and back of the skirt.
Measure the width of each panel and divide it by three. Your answer is the number of curtain tabs you need for each curtain. Cut an 8-inch cord for each curtain tab.
Fold each piece of 8-inch cord. Pin the crease to the top width of the skirt, spacing each tab out every 3 inches. Sew these in place using nylon thread and tiny, tight stitches.
Tie the tabs around the curtain rod in bows or knots. Push out the sides of the curtains to the right and left sides, respectively.