I've only tied one quilt. The backing was fleece, so I just whip-stitched where the sashing on the front crossed. Then I sewed 1/4" satin ribbons on and tied them, sewed them so they would stay tied, and fraychecked the ends. OK, a little too much?
I also saw a pic of someone who sewed buttons every 6" - used plain sheets or fabric or whatever, with a high loft batting, and the buttons were buttons her grandkids have played with for years. Pretty neat, I thought!