You can just say "Thank You", and should sooner rather than later.

This turns out to be almost exactly the one year anniversary of me writing a letter of gratitude to a blogger whose work I really appreciate. The reply I got was roughly “Thank you! A note like this makes my day”. It’s something I absolutely can and should do more of. Recently I sent a note to a small musician when I realized their song had been popping into my head for nearly 15 years. I…