I've added beaded bookmarks to my Etsy shop! I have some shepherd's crook style and book thongs. They're fun and functional. A teacher friend of mine suggested the book thongs and she should know. She and her boys are avid readers and they even beta tested them for me. I was holding my breath til I heard from them. Fortunately, they like the slightly heavier cord that I use and the color combinations worked too. Here are a few examples.
Peach and Pearl Book ThongRed and Black Shepherd's CrookPurple and Silver Book ThongTurquoise Crook