I enjoyed celebrating Valentine's Day with my husband when we were together; we usually spent our time together in private rather than publicly and we didn't do the chocolates / flowers / balloons thing. My nieces often sent me "Happy Aunt's Day" cards in lieu of Valentine's Day cards, the first few years after the divorce. I was grateful to be single but I also felt some sting that day, so that was really nice.
The last few years, being single, I didn't mind any of it but I still mostly avoided the stores even more than usual. All the RED EVERYWHERE and the candy and horrible but still sometimes tempting, toxic sweets displayed everywhere... I usually celebrated "Galentine's day" on a neighboring day via dinner out with girlfriends.
This year I'm in a relationship but he doesn't really celebrate holidays so although we'll be spending the evening together, I don't think it will entail anything obviously Valentiney.
My sister sent me pics of this card. As introverts, we both appreciate the sentiment. As frugal (cheap?) shoppers, the picture was better than an actual card.
Valentine's Day at our house has turned into Be Ultimately Cheesy Day. Lots of Champagne, which makes the rest of this very pleasant. We have in the past made hard lemonade from scratch with bread yeast, put some pink food dye in it. It takes about 4 days in a large OPEN glass container on the sink. There is a recipe called Skeeterpee. Store any extra in the refrigerator in bottles with fabric over the top fastened on with rubberbands, so the yeast can off-gas and not make the bottle explode.
We have a movie marathon of movies with Valentine's Day as a theme, Valentine's Day with Ashton Kusher, The Lake House with Keanu Reeve, and a couple of favorites, Before Sunrise with Ethan Hawke, The Holiday with Cameron Diaz. The internet is full of suggestions.
Read the history of Valentine's Day from Wikipedia and how other countries celebrate it.
Eat red food; red snacks with the movies, sphaghetti and lasagna qualify.
This year I'm going to try to make chocolate covered potato chips, putting together two of our favorite things. Sweating this one a bit, as I haven't tried it before.