Holiday greeting cards

I am about to send out Thanksgiving cards to all past customers.
Will hand address and sign. Return address on back of envelope with name, address and web site. It is something I've been doing for about 5 years. Keeps my name out there, shows my appreciation for their business and usually generates a few leads.
I elected to do Thanksgiving as opposed to Christmas since there isn't as much mail during Thanksgiving. What are you guys doing?
Anyone have any feedback with calanders?
Sage