What kind of drapes?

I would either get drapes in a 'pop' color, like a dramatic red or a deep plum that will pop out in the room. Or, if you want to still get good light in the room, get some sheer curtains in white or something like a white with a design etched on them.

I agree with Dysko- something that give you a pop of color or pattern. Or some sheers in a neutral color.

You could use sheer draperies to soften the room with out making it look heavy. you can find sheers in lots of colors... some with patterns woven into the material itself... you can even find sheer material and make them yourself... but be aware that most sheer material ravels really easily.... use an overlock or serger to solve this problem ... or a fraying preventative like "Stop Fraying" available at most sewing supply stores.

If you do not require privacy then drapes with grommets would be the easiest to install. Buy some really nice rods and put panels (usually 50 inches wide) on either side. If you need the privacy then double up on the panels. Drape installation should be at least double the width of the window so that they do not look skimpy.

I would get long sheers. Or maybe just valances. I love windows and it looks like you have a beautiful view.

I like drapes that are short enough only to cover the window or blinds because we have pets and long drapes are hair magnets. But some colorful drapes would help add some life to the space. Also throw rugs to match the drapes would look nice and add much needed color to the space.

I would put up loosely knit drapes just on the edges of the windows (kind of almost burlap loose knit type) and soften it with one of your favorite colors or pick on color from your living room. Also, I would find a pretty round dark brown rod with soft round ends.

I would hang light weight, but not sheer; white curtains, that are hung as high and as long as possible. You have a beautiful arched window top and I would show that while having the softening effect of the curtains.

Amy has my vote. Hang rods high and fabric to the floor. JC Penny has an awesome selection of the window treatments. Avoid drapes, too heavy and hide the architecture you paid good money for. Think flowing and loose. Look at the window scarfs and various applications. Books are available at the local Home Depot or go on line.

Have you considered an accent wall. Keep the color like the outdoors. Try Behr, Riviera Sand or Behr, Rye Grass. Paint only the wall where your arched windows are and use white window treatments. It will be lovely.