Swag It

• A swag adds interest and a decorative element without obscuring the beauty of the window. Choose a lightweight fabric that complements your décor. You can drape the swag only at the top of the window, or have the ends trail the length of the window on either side. Install a hook on the wall at the center top of the arch and on either side of the window at the bottom of the arch. Drape the fabric from the middle hook, let it droop down a little and catch it up on the side hooks. You can add a decorative rosette in the middle if you like.
  
  

Blinds

• You can order custom blinds made of wood, fabric, or other materials to fit your round top window. These radiate like a fan from the bottom center of the arch and come in a variety of colors and textures. For a cheaper alternative, but one that isn't as convenient, look for a large paper or cloth fan that fits your window. Open it and prop it on the windowsill. This works particularly well in an informal setting.
  
  

Curve It

• You can purchase flexible curtain rods that allow you to follow the curve of your window. Install these just inside the top of the window. These work best with lightweight fabrics. Or fill in the arch with shirred fabric that blossoms like a sunburst from the bottom center of the arch outward. You can add a decorative rosette at the bottom center if you like.
  
  

Straight On

• One option is to dress the lower portion of the window with conventional curtains, blinds or drapes and leave the upper, arched half open.
  
  Or hang a straight curtain rod the width of the window above the top of the arch. Then install conventional drapes. Draw or drape these to one side to reveal the arched window, or cover the whole thing for privacy. If you have a pair of round top windows, drape the curtains on opposite sides for a balanced look.