Keep it fairly short. There are times when you may want to write a longer thank-you letter (to a teacher or close loved one, for instance), but for most situations, three to five sentences are plenty.

The Duke and Duchess of Sussex sent the bike shop a sweet thank-you letter for Archie's gift. Instagram/maddogsbikeshop Archie was born on May 6, 2019, and has a younger sister, Lilibet, 2.

I realized that I've always written thank-you notes from a place of guilt. I recently decided to stop writing them, and I'm not making my kids write them, either.

But to answer the question you pose at the end of your letter: If you want your in-laws to know you’re not pleased with their gift, skip the thank-you note altogether this time.