You can get fancy, but the simplest way I know of is to iron fabric to freezer paper and write as much information as you want with the pigma pen, then applique to the back of quilt. If you are using a solid back, rather than a print, you can actually write on the quilt back. I have been known to do that a time or two. :oops: I like to be a bit more "fancy" however. But like Shelly said..........DO IT!! I have a couple quilts my grandmother did, (many years ago) without labels of course, so I made a label for them. I stated the date was unknown, but approximately ???? and put a picture of grandmother on the label. One of the ones I have was made especially for my grandfather, (grandma told me!) so I added that info also. Good luck with what ever method you use.
Phyllis