Measure the height of the window, and add three inches. Measure the width of the window, and add two inches. Use these measurements to determine the yardage needed for the lace shade.
Cut the lace fabric to the measurements you determined in Step 1. Fold over the top, unscalloped edge of the fabric 1 1/2 inches twice to the back (the side of the fabric that shows the stitching), and pin it in place. Sew a line of stitching at the hem edge to create a rod channel. Fold, pin and hem a quarter-inch twice on the vertical sides of the lace shade.
Cut the wooden dowel to the width of the shade, using the saw. Sand the edges of the dowel, and paint it the color of the lace. Let the paint dry for three hours.
Sew both ends of two-inch strips of ribbon to the back of the shade, placed two inches from the scalloped edge. Position the ribbons vertically, and space them every three inches to create a dowel channel. Slide the dowel into the channel made by the ribbons.
Sew the center points of 12-inch pieces of ribbon to the top edge of the lace shade, positioned six inches apart. Insert the tension rod into the shade's rod channel. Open the shade by moving the dowel to the tension rod and fastening it with the ribbons tied into bows.