When to Write a Thank You Note

The Art of Manliness explains the art of writing a thank you note:

"Gratitude is a virtue every man should cultivate. Yet gratitude means nothing if you haven't mastered the art of expressing it. A man should use every opportunity to express to those around him how much he appreciates their love, support, and generosity. One of the key ways of expressing gratitude is the thank you note."

• When you receive a gift
• When someone performs an act of service for you
• When someone goes above and beyond what is asked of them
• After a job interview
• When you stay overnight at someone's home.
• If someone shows you around their town or city when you're vacationing there
• When someone has you over for dinner.
• When someone throws a party or event for you.

Basically anytime someone does something extraordinary that warms your heart because there's never a wrong time to write one.

Source
"The Art of Writing a Thank You Note." The Art of Manliness. 23 October 2008.