I made my own blackout curtains. I added an additional spring-tension flat drapery/cafe rod on each of the bedroom windows. They just fit inside the valance in front of the day/night shade. Then I purchased some room darkening drapery lining, cut and hemmed it to size and sewed a channel for the rod. I like to leave the side curtain in place all the time, but leave the day/night shade pushed up to keep the sun from deteriorating it. I put the back one up as needed to block the light.
From Facebook post on 5/21/2012