Add re-claimed exterior shutters to a window. It's a wonderful way to bring texture and color into a room. Paint them, stain them,or leave them as found!
Drape a shawl, quilt or left-over fabric over a pole. It's an easy way to use favored items and dress up plain windows. If you have existing blinds or shutters you add softness and color instantly.
Don't need privacy? Add some lacy fabric remnants for softness. Have a damaged silk scarf? Fold it, twist it, and hang it over a window for an interesting effect. For that matter, consider using dried or faux greens, twigs and other items that accentuate your decor.
Pretty aprons, dishtowels, and other soft cotton fabrics make great window toppers, as these do. They filter sunlight and add country charm. Sew on trim or clip on pins, earrings, seashells and more for a custom design.
A napkin draped over a ready-made plain shade adds wonderful color and pattern. Hang or sew on fringe, old earrings and buttons, and other found objects, for a more interesting appearance.