There are lots of ways to label a quilt and I do it the easiest way possible. After the quilt top is created and photographed, I insert the photo onto a Powerpoint slide background. I add text defining the piece, and then print the full color image on print ready fabric sheets. I generally leave the image full size ( 8 1/2 x 11), print and press the plain white margin to the back before putting it on the finished quilt back. It's done fast and easy. My quilt for this label has a bit more work before being finished so it's currently seen on the kitchen table.
I always include the following on the label...
The Quilt Name
Materials used on quilt top
Batting content, and backing type
Your artists statement about the piece
You may add other things about who it is for, on what occasion, where presented.