Explain why you need them. Main issue is to include something that says you heard something that was said.
Amount of work should reflect the value of what you received.
6" x 4" postcards (not sure what these are)
My thank you to Craig Cutler for lighting equipment
Thank you for the Garamond, Roland Hoover
Happy birthday Roland Hoover
Thank yous from others
Jim Culley's books for Werkman experience for his grandchildren
Ann Lemon's "100 things Ray taught me"
Link to a good artlcle in MentalFloss about 7 Smart Tips for Writing a Proper—and Professional—Thank You Note.