I've started designing some individual ones that I produce on my computer. e.g. for friends who've got a ragdoll cat I've used an image of a ragdoll on the front and included links to Christmassy videos of ragdolls on the back. Similarly, for friends who've recently adopted a retired greyhound, I'm working on a card with a Christmassy pic of a greyhound on the cover.
I've yet to design my 'general use' cards for this year though. I need to come up with a decent idea and then source the graphics from the web, as with this one I designed a couple of years ago:
http://www.upl.co/uploads/Cardpicture1540229344.jpg