I just use them wherever I want just a little bit of ribbon, because they are so easy to tie the ribbon onto...here are a couple simple examples from my gallery:
Distressed photo by nottoocreative at Splitcoaststampers (hard to see but the ribbon is tied to it with the WW tags hanging from it)
Be Rustic first upload by nottoocreative at Splitcoaststampers
They may not be fabulous cards overall, but at least you can get the idea I hope! I would use them more if I had more colors (I just have the nickel ones right now) so I could give examples of where I COULD have used one (I used a staple or just glue instead)...
HTH!