Each year, Facebook founder and CEO Mark Zuckerberg gives himself a personal discipline challenge. In 2013, it was to meet a new person who doesn't work at Facebook every day. In 2010, he set out to learn Mandarin.

In 2014 Zuckerberg revealed that he is challenging himself to write one thank-you note each day.

In a Bloomberg Businessweek cover story he vowed to write "a well-considered thank-you note every day, via e-mail or handwritten letter." His reasoning: “It’s important for me, because I’m a really critical person. I always kind of see how I want things to be better, and I’m generally not happy with how things are, or the level of service that we’re providing for people, or the quality of the teams that we built."

Douglas Conant, the former Campbell's Soup CEO, takes this practice to the next level. Conant says he wrote at least 30,000 thank-you notes to employees over the course of his 10-year career. He committed about an hour each day to writing thank yous, an eternity in a busy Fortune 500 CEO's schedule. He usually made time for it during his commutes or while traveling

Conant said, “[Most senior executives] develop this skill set that's largely based around critical thinking. They get really good at it, and tend to really develop that muscle" of trying to critique things more than compliment them.

Tom Peters, a management expert, adds that the note should also be handwritten. When it comes to thank-you notes, “barely readable scrawl is best. It really says you're being personal.” Peters also says they're particularly effective when sent to low-level employees who will be more impressed to hear from someone at the top. “But we're all suckers for it,” he adds.

Possible Preaching Angles: 1) Home; Family; Parents; Body of Christ – Imagine how our homes and churches lives would benefit from a handwritten word of praise. Parents could write a brief note of appreciation to their children, and children to their parents. 2) God; Thankfulness; Thanksgiving Day – How about handwriting a note addressed to God during your devotional time, listing all of the things for which you are grateful?