Whatever the type of treatment your windows have caring for them to make them look the best matters a lot too. Most of the window treatments that are available on the market are easy to care for and can be either vacuumed or brushed down with a duster. Most blinds can be cleaned this way without the use of soap and detergent.
There maybe other type of window treatments like the wood shutters which are painted over to match your decor that may need to be washed down in place using soap and water and then dried out with a dry cotton cloth. Caring for blinds that are made of metal is mostly by using a vacuum or by using a dust brush that can remove the dust. Using water and soap is not recommended. If your blinds or shades are custom made then maybe it is good to contact your dealer or supplier for the right method of cleaning them.