Make a cornice valance if you prefer a more structured look. Build cornice boards made of wood and moldings. Add carvings and wood relief to decorate the front. Paint the wood with a color that will complement the room or the fabric used for the drapes. Upholster the wood with cotton batting and matching fabric to soften the appearance. Choose the ornate design for a more formal look; keep it plain and simple for an informal look.
Definition; it is generally any horizontal decorative molding that crowns a building or furniture element— the cornice over a door or window.
Types of cornices
Box cornices enclose the cornice of the building with what is essentially a long narrow box. A box cornice may further be divided into either the narrow box cornice or the wide box cornice type. A narrow box cornice is one in which "the projection of the rafter serves as a nailing surface for the soffit board as well as the fascia trim. This is possible if the slope of the roof is fairly steep and the widths of the eave relatively narrow. A wide box cornice, which is common practice on houses with gentle roof slopes and wide eaves, requires the use of lookouts to give it support and to provide a surface to which to securely attach the soffits. Box cornices often have ventilation screens laid over openings cut in the soffits in order to allow air to circulate within the cornice.
A close, closed, or snub cornice is one in which there is no projection of the rafters beyond the walls of the building, and therefore no soffit and no fascia. This type of cornice is easy to construct, but provides little aid in dispersing water away from the building and lacks aesthetic value.
A close cornice
In an open cornice, the shape of the cornice is similar to that of a wide box cornice except that both the lookouts and the soffit are absent. It is a lower-cost treatment that requires fewer materials, and may even not have a fascia board, but lacks the finished appearance of a box cornice.