You can print with your printer on fabric (purchased or made/prepared yourself), and sew it onto the quilt. I usually sew mine under the border, and then slip-stitch the two remaining edges onto the quilt.
you can handwrite onto muslin (stabilize by ironed on freezer paper), and sew into the quilt.
You can write directly onto the quilt (test on some of the fabric on which you plan to write first).