Your label is part of your personal history. Put as much information as you want--I put lots--with at least your name, the date and the location. I use Pigma pens on muslin. I border the muslin rectangles with a fabric from the quilt and put it on the lower left hand side of the back. But there are no rules. Do what you feel comfortable with. Just be sure you get that label on there!
froggyintexas