I used to have a pen pal who would put little stickers on the envelope, and I always thought it was a classy touch. She also put just the barest hint of perfume on the paper because she knew I had a crush on her and she liked to torture me just a little. In fairness, I liked the torture. Hi Heather, wherever you are.
My high school sweetheart absolutely did the perfumed letter thing too, although I, being the oblivious young git that I was, never even realized. Much later on I'd just wonder why the drawer where I stored the letters had such a strong and pungent smell.