You can put a quilt label anywhere on the front or back, I guess the most common place is a lower back corner. I include quilt name, who it is for, made by, and the date always and then feel free to add any additional info. A number of different ways to "write" the label can be used however a sharpie or other permanent marker normally used for paper is not the best to use for your label. It will sometimes bleed and eventually fade when washed. There are pens made to write on fabric, one being the Pigma pen. I'm sure others will chime in on what they use--in the end it is mainly up to you what you include and how it is written.