How to hang a cornish board for windows?

Question

How to hang a cornish board for windows?

Answer 1

I'm assuming you mean a cornice board.  

Hanging the Cornice Board

"L" brackets are used to hang the cornice board to the wall. Be careful to avoid the window casing when positioning the brackets. (See the third picture, above, of "L" bracket.) Using two brackets (three for a long window) attach brackets to wall about 1 to 2 inches above the window. (You want to cover the window covering's hardware.) Attach one brackets about 1/3 of the window length from the left and one 1/3 of the length from the right. (If using 3 brackets, attach one bracket in the middle.)Set the finished cornice board on the brackets, and attach the top of the "L" brackets to the underside of the top piece of wood.

This picture (see above, third picture) is shot looking upward from the blinds to the bottom of the cornice board. The "L" brackets are attached to the bottom side of the top piece of the cornice board. After attaching with the "L" brackets, the cornice board will be firmly attached to the wall and the top can be used as a shelf to hold plants, knickknacks, or whatever you desire.