Measure the distance from the curtain rod to where the curtain is going to stop using a measuring tape and add 4 inches. This is measurement "A."
Measure the distance from one edge of the window you want the curtain panel to cover and multiply by 1.5. This is measurement "B."
Cut a rectangle of sheer fabric that is as long as measurement A and as wide as measurement B. This is your panel.
Fold down the two edges equal to measurement B and one edge equal measurement A twice, creating a fold that is 1/4 inch deep both times, and pin the fold flat.
Sew the folds you made down using a sewing machine or needle and thread, removing the pins as you go.
Fold the last remaining raw edge down twice, the first time creating a fold that is ¼ inch deep, and the second time creating a fold that is 3 inches deep, and pin the folds flat.
Sew along the bottom edge of the fold to create a channel running along the top of the curtain, removing the pins as you go. At this point, the teen’s curtain is ready to hang.