I cross stitch all my labels. I use graph paper to create the lettering and figure out line lengths and line spacing. After stitching the lettering in a color that complements the quilt and that is dark enough to read, I add a 1/2" fabric border using scraps from the top and hand stitch it to the back.
My friend types her label text on the computer in a font she likes, prints it, tapes it to a light box and traces the wording onto a piece of white or off-white muslin using an ultra fine point permanent marking pen.
There are lots of ways to create labels and you have to find your preference; the important thing is to label the quilt so others know who made it, for whom it was made, when it was made, etc. Too easy to forget those facts as time marches on.