I'm still a fan of notecards and getting mail, but I'll extend this information to include thank-you emails as well. There are many situations for which it is appropriate to expend some extra effort to write a thank you - for this post, I'm referring to a personal thank-you.
Yes, you should write these as often as you receive a kind gift, word, or deed. This is something for the whole year - not just one day in November. Or even just for the end of the holiday season overall.
For Beginners - usually small children, but I'll let you self-identify.
Salutation - remember that from Charlotte's Web - a greeting. Dear So-So (feel free to use a nickname, pet name, or, novel idea, their real name).
Thank you for the ___________. It is really nice. I like it. I will use it to ______________.
Closing - you can use Thank you (again), Sincerely, Love, Best Wishes, Kind Regards, etc.
Your Name (no, sign your actual name, don't write "your name")
Salutation is the same: "Dear So-So,"
A general (but genuine!) nicety: "It was so good to see you yesterday." "What a wonderful surprise to receive your note in the mail!" Maybe a follow-up (if you're feeling slightly above average): "Our conversation brought back great memories from..." or "I can't wait to see you in...."
Then, mention the gift with a thank-you in there somewhere. "Your gift was so thoughtful - I have been looking for a unique accessory to match the new sweater I bought in the summer and the earrings were perfect!" Or, "The gift card came at a perfect time - I've been stuck on a project and this was exactly the prompt I needed."
A follow-up is a good idea here otherwise it sounds like a beginner note - it can be something directly referencing the gift or the friendship.
And, the Closing can be the same as a beginner: Sincerely, Love, Regards, Thanks, etc.
What if a gift is not particularly something you're glad to see? I remember receiving a holiday sweater from my grandmother that I couldn't honestly say I was going to wear. I don't remember what I wrote in that thank-you letter, but I've come up with some alternatives in the years that followed. Remember, be sincere. In these cases, focus on the relationship.
For something you'll re-gift: "Thanks for thinking of me in the hustle and bustle of the holiday season - I know (name of gift) will bring joy to many people this year."
For something you'll never use: "Thanks for thinking of me in the hustle and bustle of the holiday season. The (gift) reminds me of you everytime I see it!
However you arrange your sentences, do it, be sincere, and whatever you do, don't respond to a cash gift the way my brother did to my grandfather when he was younger: "Right color, wrong size."