Among the foreign traditions I've enjoyed here in the US is opening presents on Christmas Eve, rather than Christmas Day, the more common US practice. I was introduced to it when I lived among descendants of Scandinavians in the Upper Midwest, especially Norwegians. But my own roots are strong, and I'd try to leave a few presents unopened until Christmas Morning.
Another was eating certain foods on New Year's Eve, to ensure good luck in the coming year. But what you eat depends on the ethnic/cultural group. I've had to eat shrimp, or pickled herring, or black-eyed peas, or things I can't remember. Maybe you know of some.
Of course being partly Irish I had to do all of that "wearing 'o the green" stuff on St. Patrick's Day. Odd, because I understand in Ireland the day is not the big event it is here in the US.
So I had to march in parades as a kid, all decked out in green, and attend a string of house parties hosted by that side of my family. Plus we always had corned beef & cabbage that day on our own table at home, with plenty of potatoes and Irish stew. And for at least a week before my Grandmother would sit me on the piano bench with her while she played authentic Irish songs, accompanying her in the lyrics.
Later in college I would go with friends to New York City Irish bars to get drunk, often involved in brawls that got us thrown out onto the sidewalk. And then we'd go to the next bar, and do it all over again. Today the best I can manage is drinking some green-colored beer, with nobody Irish there at all, and certainly not at an Irish place. Ah, well, I guess that tradition is dying.