Study nature, love nature, stay close to nature.
It will never fail you.
- Frank Lloyd Wright
Another option is to cut a piece of paper with the decorative scissors and then mount your photo on that background with double stick tape...see below.
Either way, layering is the idea. Think about mixing colors...for a high contrast or a more subtle look. There is no right or wrong...play around and see what looks good to you!
Also, being a bargain hunter, I wanted the freedom to check out discount stores too. The problem is, when you do that, you don't always have many choices on size.
What I ended up doing is finding two different thinner panels...that might be used more for decorative treatments on the sides...and sewed them together to create a fuller, custom window treatment.