My father is a Lutheran pastor, and his favorite painting is The Starry Night by Vincent van Gogh. I saw in the Postal Bulletin that Bethlehem, KY was offering an "Eastern Star Station" pictorial postmark in December. Using visual effects software, I added a "Star in the East" to van Gogh's painting and gave it the title The Starry Bethlehem. I laser-printed cachets onto two envelopes, applied a blue "geometric snowflake" stamp to each, and sent them off for the postmark.
I mounted the better of the two in a floating frame (that is not a technique I recommend for preservation!) and gave it to my father as a gift.