Hand-made greeting cards are a longstanding tradition in my family. My sister and I both got really into it when I was about 10, and invented our own imprint labels, even though it was usually only family who received our cards. (Hers was The Pony Express. Mine was Wolfling Express. Then we realized that the word we were looking for was either Press or Expressions, not Express.) Our mom collected these cards somewhere, and I'm sure they're all still packed away somewhere in her basement.
I don't send cards very often any more — most occasions these days seem to merit a phone call or visit instead — but when I do, I usually still make them by hand. Partly because decent greeting cards are ridiculously expensive (seriously), but mostly because it's way more fun and way more enjoyable for the recipient. Especially if you can work an inside joke right into the artwork.
This I just made the other night as a thank-you card for my grandmother. I'm regretting the crappy black "framing", but it was late and I was tired, and she'll love it anyway. Grandmothers are awesome like that.
Markers, ink, and a bit of colored pencil on ACEO-sized bristol, stuck to blue cardstock by inserting Tab A into Slot B four times.