I sign my name and date my work if there is somewhere to put it, on the other hand someone orders something and doesn't want it signed no big deal.
My grandfather was a wood carver, about a year ago my uncle saw a Christmas ornament laying in a parking lot, he was only 80% sure it was my grandfathers work , until he picked it up and had my grandfathers signature on it. If he would have not signed it deep down we may have know it was his work but could not have proved it.