Measure your windows to determine how much material you will need. You may choose to use one to cover the entire window or two panels placed side by side. Also determine if you would like the length of the scarf valances to extend to the floor or to stop at the bottom edge of the window.
Choose the way that you would like to incorporate the two colors. For example, you may place two opaque panels next to each other or drape one sheer scarf valance over a darker colored scarf to create a layered effect.
Pick the two colors of the valances. Match the room by choosing colors similar to the carpeting, paint and furniture, or choose an entirely different color to add a contrast.
Purchase the valances at a store that sells window dressings. Businesses that offer drapes and different types of blinds usually sell scarf valances as well. Alternatively, you may purchase sheets of silk or a fabric store and use them as valances.
Drape the valances over a curtain rod in your window so they create a wavy look across the entire rod. Since you are using two different colors, you may choose to brush one to each side during the day.