This year, I was asked to put together our Christmas in July luncheon at the company where I work. I couldn't find a darned thing close to cute Christmas-in-July invitations, so..... I made my own!
I picked up a pack of blank invitation cards at AC Moore and simply stamped Christmas trees on the front with green pigment ink and the invite part with black ink. Then I smudged the edges with lime green decorative chalk.
Easy peasy.