Dear {Blood Donor},

You don't know me, but you saved my life. I wouldn't be here today if it weren't for your blood donation. From the bottom of my heart, thank you so, so much for your kindness and generosity.

Sincerely,
{Your Name}

Dear {Hosts},

Thank you for having {partner} and me at your dinner party last night. We appreciate the effort you put into making sure we had a good time. The food was delicious and we really enjoyed your company.

{Partner} and I are having a few friends over for {wine night/Scrabble night/etc.} next {day of the week} and we'd love for you to join us. We hope to see you then!

Best,
{Your Names}

Dear {Host},

Thank you for inviting me to dinner last night. The {dish} was absolutely delicious! I'm so lucky to have such an amazing host and cook as my friend. As always, I enjoyed spending time and catching up with you. I hope we can do this again soon.

Love,
{Your Name}