I did it! I created a card using Adobe Illustrator. As part of my grand scheme to start a small business I downloaded a 30 day trial of this very expensive software. It's a huge learning curve - to the point where you need a degree in computer graphics to navigate it I think.
Anyway I am pretty pleased with my first efforts. It's not a totally original design. I've been inspired by things I have seen in shops and online but I didn't copy it directly from anywhere.
I printed them with my home printer on acid free fine water color paper postcards.
I've printed out a little set of five so if I have your address you might just be getting one for Christmas this year!