I have fond memories of Kentucky Wassail from this album

Word are available here. It's just a lot of fun to sing.

Hah! We had that one!!! Maybe I should get it!

As most Xmas traditions have roots in ancient Pagan practices, you can pretty much do what you do now. :-) Just leave Jesus' birth out of it, and celebrate the rebirth of the Sun King (who is reborn on Yule because it is the date when the sun reaches its furthest Southern setting point, and the days begin to get longer from that point).

Rebirth of the Sun. Birth of The Son. Clever, those Catholics were.

There is copious information online about Yule and the other seven major Sabbats for the curious.