While reading a good reference book recently I was wishing to have a few permanent bookmarks, and employed a quick craft that I learned at girl’s camp in my youth.
1. Take a sturdy piece of cardstock, or better yet thin cardboard.
2. Securely tape ribbons or embroidery floss to the top, with scotch or packing tape.
3. Open the book wide, making the covers almost touch, to slide the cardboard into the spine of the book.
4. Tuck the ribbons/string in the pages you want marked!