When we moved into our house 6 years ago, we needed to cover all of the windows quickly and inexpensively. So, I ordered plain roman shades and put them up on every window.
I like that they are simple and kind of blend with anything..... I've replaced a few with bamboo but wanted something lighter in the kitchen. I hated to get rid of the shades because they still worked great, so I thought about covering them.
I bought a fabric shower curtain at WALMART and simply wrapped the fabric around and glued it to the back with fabric glue.
It gives it a totally different look for about $10!