In addition to buying curtains, you'll need a curtain rod to hang them on. This is a long metal or plastic rod that is secured above the window to hold up the curtains. They are usually extendable, so you can make them slightly shorter or longer if needed. The size you buy will be based on the length of your window. Other than a curtain rod, you'll need a measuring tape, level, and some screws to get your curtains hung.