My usual way of labeling quilts is with a twill tape label sewn under the binding on one of the lower corners of the quilt.
|For an extra long label I zig-zag stitched two pieces of twill tape together.|
I write my labels with Sharpie "Stained" fabric markers, heat set with an iron. I have the four basic colors and they all seem to work well. I haven't had any issues with fading or bleeding in the wash.
I always include the name of the quilt and the month and year. Usually I also include my name. If the quilt was made by a group of for a particular event I also include those details.
When I run out of twill tape I just do the same thing with a length of fabric sewn into a tube and top stitched along the folded edges.
I really like this method of labeling for its simplicity and ease of use. Be sure to go to the linky to see how everyone else labels their quilts!