In the past I have sent thank you notes but now on a fixed income stamps are getting a bit high and add on the note card and envelope and it is more than I feel I can spend on my budget. I have never expected a card as long as the gift is acknowledged. I have received gifts that I am not thankful for but the thought was wonderful. So I do let them know I received it and thank them for the thought. It is a new age and each to his own. If you want to send thank you cards go for it. But it is a personal thing. I don't know if I would attach an address label unless to let them know who it is from.
Lynda