I started by making a cornice box for my morning room. I love this easy tutorial from My Old Country House on how to make an "easy as pie" cornice. In the tutorial, foam core board is used to build the box. I used an old sign from my husband's job that was made of gator board (which is kind of like a plastic foam board). Keep an eye out, you never know what could work for making a cornice.
Gator board can still be cut with a utility knife, so I followed the rest of the directions just the same. I laid it all out on my morning room floor and went to work.
My little dog Daisy likes to help too. Here I'm covering the board with batting.
The wonderful thing about making your own cornice or curtains is that you can pick your own fabric. I loved this plaid fabric and the colors went great with my rug.
Keep in mind when you pick your fabric that you'll have to keep horizontal lines straight or if there's more pattern that you'll want to center it on your fabric to make the entire image fit. Do a dry run before stapling/taping.
Since I didn't put curtains with my cornice, I didn't need to use a curtain rod. I bought a pack of "L" brackets at the hardware store to hold up the cornice. I used three because of the length (one on each end and one in the middle), the cornice box just sits on top, there was no need to screw the cornice into the L bracket.
And there we have it. A rather large cornice box for about $30 and most of that was the cost of the fabric!