A lot of nonprofit thank-you messages say something like this: "Thank you for being our partner...."
That's about as thrilling to the donor as telling her she has nice elbows.
Donors don't give in order to be our partner. They give to have a positive impact on the world in some specific way. And that's what you should thank them for.
Not for what they did in their relationship with you. It's another way to put yourself in the donor's world and not your world. Which leads to better results every time!
Play: The right way -- and wrong way -- to thank your donors (right click or "save as" to save the file for later).