Things Which Ought To Exist

Remember when you were a kid, writing the dreaded thank-you letters on the nice notelets your aunt gave you for Christmas? "Blank inside for your message"

How about "Blank outside for your image" - blank-fronted notelets for you to draw a nice picture on, pre-printed inside with
Dear ________,
(delete as applicable)
* Thank you very much for the _________________, it was very nice/fun/interesting/delicious.
* Thank you for having me to stay, I particularly enjoyed _________
Love,
_________

:-)