Often you have to be clear about what you want. If you don't get thank you notes, did you ever mention that you like or expect them? Try giving them a set of thank you notes at thanksgiving and let them know they could use them at Christmas and birthday time. Educate them. Also, I understood that etiquette dictates that if you say thank you in person, you are not expected to send a thank you note. One of my biggest pet peeves is when one person gets angry at another because he/she did not live up to an unsaid expectation.