I put my name and the date minimum. If needed I also put the name of the pattern and pattern maker---it's nice to give credit where it is due. Also if I didn't quilt the quilt--I add the quilter's name and location and my location.
I hand write mine (handwriting is getting rare) with a sharpie pen and heat set it with my iron. And yes--sometimes I flub it and have to do a second one.
I pick out a light-colored fabric with tight weave---sometimes I flip a fabric over. It's usually a fabric used on the front of the quilt. I like to iron on a piece of freezer paper on the back--it makes it easier to write on the surface.