Every family tradition was started by one person who decided to try it twice.
CREATIVITY
CREATIVITY
Traditions look ancient from the inside, and every one of them began with somebody repeating a small good thing on purpose. The second occurrence is the real threshold, because that is when other people start expecting it and the upkeep stops being yours alone. None of this requires permission or a special occasion.
Take something that went well recently and do it again at roughly the same interval. Give it a name, since a name is what makes people remember. Two or three rounds is usually enough for it to belong to everyone.
Which small ritual could you start with your family?
Free, with nothing to buy inside it.