LOR thank you notes/gifts

Hi Everyone!

I've been trying to find some advice on when to give thank you notes to your LOR writers, what gift is appropriate, etc. and haven't been able to find a consensus. With my situation, I sent quick thank you notes when I was asking for the LORs, and wanted to wait until I received my decisions to send a more formal, handwritten note.
Unfortunately I was wait-listed, so I'm not quite sure how to put in the letter that I will be re-applying next year and will probably need another reference!! And if I should gift them a small gift card as a token of my appreciation for this past year?

If anyone has any advice or experience with this I would so greatly appreciate it!! Thank you!