I try to make a special meal for my family at home, just to make it a low key day. We don't really go "all out." We never go out to eat on that day because it is SO crowded then!
I am not a "flowers" person and DH knows it. In fact, he knows that I am perfectly happy with a Milky Way
I still have a first-grader so he makes Valentines and things like that, for us, at school. And those are probably the most precious things we can get on that day.
I do buy the kids a few packs of those conversation heart candies, because they like them. But mostly, we don't bother spending money on "stuff" just for the sake of giving a present.