I think it would look lovely with your idea of a wreath of red berries in front of the glass. Maybe 2 - one for each pane. I wouldn't put anything behind the glass because it would take away from the window itself, which is the focal point you are wanting.

Be sure to take a picture and let us know what you did with it!

I have a couple of old windows that I use as art in my livingroom and bedroom. The one in the living room has ivy, raffia, and wooden stars (to match my Americana theme). It is painted barn red. The one in the bedroom is white and has a rose and ivy swag on top of it (to match the border in the room).
Maybe you could find a small quilt in colors that match your room and display it behind the glass. You could also create a shadow box with sentimental items that match your theme. You could also choose flowers in the colors you mentioned, press them and then decoupage them to the glass in a random pattern.
I think this link has been shared before, but there are some good ideas there.
Take a picture. We'd love to see what you decide to do.

Here is a link that might be useful: Old Windows

Thanks for the window link! Great ideas!! I have other windows to use for something and may just get creative with those also! Will post a pix when I complete my project with the large window!

I would be dying to do a glass on glass mosaic on it . . . .

Could you paint a mural to go behind it? So that it looks as though you are looking out the window down a country road? It isn't too hard if you get a slide and project it on a canvas or masonite board, then draw it. Keep the colors subdued so that it doesn't detract from the window.

A mural would be great, in muted tones of your room I think. And on canvas or board would be better so you could move it and redecorate of course.

any collectibles or sepia photo copies behind it will be nice, like necklaces, watches, hankys, lace. (hung on back would keep little hands off the items.

Or if it will fit in your sceme of deco.. make it to change with the seasons....like snowflakes, flowers, leaves in fall....in a pinch you could use the little stickon klingy (tech term of course) designs that match a holiday or season.

Decoupage family pictures, dried flower arrangements on glass so wall color shows through, maybe a combination of both?

I added shutters to just such a window and a small bird in a nest nestled near the wooden glass divider. I've also seen them done with pretty antique curtains added behind. The shutters can also have old doorknobs addes for a hanging welcome sign or such.
Lucky you.
Diana

Here is a link that might be useful: my website

WOW!! I am really impressed with all the great ideas, I was thinking pressed flowers and pressed ferns behind the glass, delicate yet eye catching in colors to match the room, could even do rice paper or tissue behind the flowers to make them more visible.