Coordinate the type of drapes you want to hang over the windows in the room with the look you are trying to achieve. For example, floor-to-ceiling crushed velvet drapes in sapphire, ruby, burgundy or any other rich, jewel-toned color will help you create a regal look. If you're going for a French country design, drapes that feature a gingham or paisley print in pastel colors are a few options. To add light and whimsy to a space, opt for light-colored sheer drapes.
Hang the curtains over the windows on decorative rods that coordinate with the style of the room; wrought-iron rods for a rustic space or brass rods with decorative finials for a regal space, for example.
Arrange the curtains. Decide how you want the curtains to lay. Pull them open and allow them to hang freely, framing either side of the window, or tie them back with decorative ribbons. Pull the curtains over the windows, and straighten them so they cover the windows, providing privacy and filtering out sunlight.
Add decorative accessories to the room that coordinate with the curtains. For example, arrange decorative aqua and sea foam green cotton throw pillows or a chenille aqua or sea foam green throw blanket on the back of a sofa or chair in a beach-themed room. A combination of black and white velvet throw pillows arranged in an alternating pattern along the back of a couch add to a contemporary design while matching gray walls.