When I shared photos of the little baby shower lunch I hosted a couple of weeks ago, I mentioned the original theme was sprinkles. Since scheduling it was a surprise I sent out one invitation to the guest of honor. I made a shaker box full of sprinkles and sent it off in the mail. My mom asked me about the card a few days later. She was curious if I had used sprinkles in it. I was puzzled (and likely snotty) when I said, "Yes, of course". Turns out they were pulverized by the time they arrived.
My mom kindly suggested, in the future, I write "please hand cancel" like she does on delicate mail. Lesson learned.