[Your letterhead, if desired; if not, your return address]
[Date of letter-month, day, and year]
[Recipient's first and last names]
[Street or P.O. box address]
[City, State ZIP code]
Dear [recipient's name]:
Mom and Dad, you are simply the best, and I so appreciate you. When I was going through those recent challenges and changes in my life, you were right there for me at all times, and I am so appreciative of you doing that. I cannot imagine going through circumstances like that without your love and support. Even though hard times are not pleasant, it is in times like those that we often draw closer to those we love.
I want to take you out to dinner soon as a little way to show just how much I appreciate you. Is this weekend a good time for you to do this? Just let me know. And again, thank you, from the bottom of my heart.
[Sender's first and last names]