A paper clip works well as a bookmark, especially if you are carry books in a bag or backpack. The paperclip won't fall out the way a loose bookmark can.
You'll never be without a bookmark if you get junk mail. Just clip off a corner of an envelope in a triangle. Either use it plain or let one of your children decorate it for you. Then just slip the corner over the page of your book to mark your place.
Since reading is one of my past times, I always have many kinds of bookmarks on hand. One of them is the simple rubber band. Every time I take a break from reading, I just insert my rubber band as my bookmark. Simple yet helpful.
This is a page about bookmark craft ideas. Handmade bookmarks are a great gift for the avid reader and a creative project for the maker.
I have lots of wallet size photos from my own kids' school photos and also photos of my friends' kids. I use them as book (and magazine or cookbook) markers...
As one of Jehovah's Witnesses, I use my Bible on a daily basis. My Bible only has 1 piece of ribbon as a place mark.