As the weather turns colder, one of the best things you can do for your budget and your carbon footprint is to better insulate your home. Here, we show you how to reduce heat loss through your windows by hanging a simple flat panel known as a Roman shade. Store-bought versions of these window treatments can run $200 or more per window, if you have them custom-installed. But with a bedsheet, leftover ribbons from gift-wrapping or old clothes, found garden stakes and needle and thread, the only cost is your time (about two hours). To maximize heat retention, instead of a bedsheet, you can use a heavier fabric such as canvas — though it won't let in as much light. Below are step-by-step instructions for making your shade from green materials. We opted for maximum simplicity, employing a design that is rolled up and manually tied. (Story: Lindsay Kurz. This article originally appeared in Plenty in November 2008.)