Making a window treatments valance
The best way of making your window treatments valance is to treat it just like a curtain. They are best lined, and in most cases also look better with an interlining. This gives them added body so they don't look too limp.
One point to watch out for - don't make them too shallow.
Remember that you normally have about 3 inches (about 8 cms) of pleats at the top (pencil, french pleats, etc), and if the depth is only 6 inches (about 16 cms), there isn't enough room for the fabric to hang properly. I'd suggest the depth should be a minimum of three times the depth of your heading, which gives about 9 inches (18 cms).
Fitting your valance
Fitting a window treatments valance is the same as fitting a cornice box, so if you need advice on this just go to the cornice box page.
The only difference is that although you can pin the valance to the board, a better system is to use "Velcro"® or a similar product. It make it easier to fit the valance, and also much easier if you want to remove it for cleaning.
There are many other ways of fitting, each manufacturer has a different method. And guess what - they all claim their's is the best way! Actually, most of them are very good and make it easy to fit your valance.
If your valance is not very heavy, and you're not bothered about light showing above the top, then you can use a valance track. These are often sold together with a curtain track, and can be attached to the same fittings.
The valance is usually attached by using normal curtain hooks which fit over the track. Some fittings have their own system, but are usually easy to attach to the back of the valance.
The illustration above shows a straight valance, but you can also shape them. One attractive shape is to curve the bottom edge down from the center, and then flatten out before actually reaching the sides. This produces a gentle curve, and is particularly useful if you have a lot of vertical and horizontal lines in your room. Giving your valance a shape softens the overall effect.
A common mistake with a shaped valance is to make the center section too shallow. This part still needs to be deep enough to conceal wall space or window frame. Make the sides deeper, and the effect will look balanced and in proportion.