Snail mail. There's something purely fantastic about it. Phones are brilliant and convenient but after a long while of nearly-obsolete letter writing, it's coming back and I couldn't be happier. While it's true that the inside matters, beautiful envelopes are a wonderful way to start the experience.
It's like wrapping a gift. The wrapping paper adds personality, whether you choose a recycled brown paper bag, perfectly folded shiny paper, or the comics from the Sunday paper. Why not give your envelopes the same care and attention? While you're at it, pair it with a perfect card.