Hang sheer curtains in front of the bay windows as part of a contemporary decor scheme. Sheer curtains allow the natural light to filter through, even when the curtains are closed, and they aren't heavy enough to detract from the bay windows. For a traditional decor, choose a treatment with a print such as flowers and add a valance above the window. For bay windows with little space in between them, hang roman shades over the windows.
Place a sectional couch in the room. Position the sectional so that one side faces the bay windows, while the other side faces the adjacent television or fireplace wall. If you don't want a sectional, you can position a couch or a love seat in the same configuration, or a couch and two chairs. The love seat or two chairs should face the bay windows, while the couch can face the other focal wall.
Add a design element in front of the bay windows. Place a set of chairs and a small table in front of them, positioning the backs of the chairs toward the windows. Placing furniture in front of the windows creates a separate space within the room. An alternative to more chairs is a grand piano or a love seat.