I initial and date all my work using small back stitched letters. I also fix a business card sized label on the inside of the frame with a small note about the piece and who it was stitched for.
I never thought about signing my work, but it makes sense, my daughter signs her drawings and I even sign my scrapbook pages... I will look on how I can do this
On my large pieces I stitch the name and the year/s in which the work was completed. I hope that when I'm long gone some of my work might be treasured, or at least be a nice historical talking point
I have always stitched my initials and year. At first I placed near one of the lower corners. Then I started hiding it in the pattern if I could. It depends on the project and who the owner will be. Good luck!