You can download the file for the mason jar graphic from the site, print it out, and then you are right to go. There were 8 tags to be made from one page.
So I grabbed one of my jars of buttons, and got started
Any shape or size can be used. Here my 8 finished gift tags
These can be pinned to your gift, or punch a hole and tie on.
As you can see, I also used some corrugated card for the backing on some of my jars, I like the different texture it gave the tag.
Remember to also keep a separate sewing machine needle for when you want to sew on paper or cardboard.