I was looking for a little bit of crazy to add to the Christmas card I designed, so when my art teacher friend said they reminded her of peppermint and should be scented, I was in complete agreement. There began my quest for peppermint oil (which wasn't difficult, they sell it at GNC and places like Whole Foods). I put a few dashes of the oil in a glass bowl, dipped a q-tip in, and went around the edges of each card, scenting each side. I also added a small dot to each envelope.
When I decided that wasn't enough, I left all of my stamped and addressed cards overnight in a closed freezer bag with a peppermint soaked paper towel (which was in a separate sandwich bag to prevent from leaking/spillage/panic attacks). Sadly I ran out of envelopes so my list was cut short. Hopefully I can send more out before the New Year!