Pine needles.
When I lived in Hawaii we couldn’t afford to buy a real pine tree every year for solstice, so we got a fake one. In order to make things more real, we also bought a spray to be used on said tree that would make it smell like a real pine tree.
When I was young, I lived in Belcarra, out past Lake Sasamat and Anmore in British Columbia. We always had a very large Christmas tree, which we would decorate not only with standard ornaments but also garlands of popcorn and cranberries — high enough, of course, so the dogs wouldn’t eat them, take down the entire tree, destroy the Great Room, and get thread tangled up in their guts. (We had a dog named Toyon who was terminally stupid, and I was known to quip “Toyon a meathead!” Somehow he survived to die of old age; I put it entirely to our making sure he didn’t earn a Darwin Award. Had to be super-vigilant.)
Those early days were, despite their numerous problems and dysfunctions, some of the happiest of my life. After my parents’ marriage — and my life — fell apart, I found myself constantly trying to re-capture the essence of those happy holly days (while simultaneously suppressing specific memories of said days).
To this day, pine needles evoke a sense of happiness, health, and wealth to me. (Which is why pine is also a prosperity association to me.)