I'm the most Kkkrackkkers of Amerikkkans so my tradition is just getting drunk off mulled wine and re-watching bad holiday movies with relatives I only kinda like.
I'm sometimes a little jealous of people who have weirder shit going on, like gremlins who slam doors and steal sausages or shitting Christmas logs. We need to bring back weird ass half-pagan shit.
It's a common myth, but no, the modern image developed somewhere around the end of the 1800s, and coke started using him in the 1930's. No idea when the red came in, but it was definitely before the coke marketing campaign, as there's cartoons from the 1910's or so that show the modern fat jolly red dude.