Would something like:

Dear Sam and Shannon,

Have a lovely Christmas and new year. Aston is wonderful and a pleasure to look after.
Thank you for welcoming me into your home and trusting me with the care of your wonderful boy.

Best wishes,
Emily


Not too slushy but a nice note all the same.

Gifts flow down and you can say the same for greeting cards.

If they do Christmas, say Merry Christmas and Happy New Year. That's enough for them.

It's the new year! let go of old baggage write a nicy nice message. Rise above it all and Fake it for the sake of the new year.

I want to include MB/DB in the Christmas card I send but don't want to go overboard as they haven't been all that great to me. I don't just want to send a simple 'Happy holidays' message with nothing else as I feel I should include a few more words. Any ideas?