I usually don't make a label unless I am giving the quilt as a gift, or I am donating it to a good cause. Then I usually make a label on my embroidery machine, back it with Steam A Seam II and iron it on the back of the quilt.
My sewing machine has an alphabet so what I used to do, before I got an embroidery machine, was either embroider on a block or on the back of the quilt before I put it together. I'd embroider something like "Made by LesLee 2014".
Two years ago I received a quilt I had made for a friend. She had passed and wanted me to have the quilt as a remembrance. It had been well used and I was so happy to see that I had embroidered "Made for Mary with Love by LesLee 2000" on it.