You see a new TV spot, like "The Night the Reindeer Died" or, my personal favorite, "Bob Goulet's Old-Fashioned Cajun Christmas."
There's a celebrity cameo! Don't see any celebrities?? Grab the nearest old person/parent and have them explain what a "Lee Majors" is.
Someone starts talking to himself/ranting wildly. Just like Christmas at Grandpa's house.
Claire calls Frank "Lumpy." Look, we've all had endearing but embarrassing nicknames. Really, "Lumpy" isn't that bad -- in high school, mine was "please stop talking to me." Oh wait, now I get it.
Frank Cross is being Scroogey. For reference, giving your brother towels for Christmas = 1 Scroogey point. Stapling antlers to a mouse's head = 100 Scroogey points. Making a fourth Indiana Jones movie = a billion Scroogey points.
You hear someone say "Merry Christmas." It's a Christmas movie, so we've gotta have that rule, right? Work with us here, people.
One of the ghosts or a disgruntled Bobcat Goldthwait starts messing with Frank Cross mentally, psychologically, or Three Stooges-style. Don't know who Bobcat is? Ever heard of POLICE ACADEMY?!?! No? Are you sure you're old enough to be on this site?
Take a shot whenever that female censor gets hurt. This will help you get in the Christmas spirit of feeling others' pain/laughing at others' pain.
Sip some Scrooge (Stoli and TAB) whenever Bobcat's boozin'.
What about HOT TO TROT? A movie where a horse, voiced by John Candy, helps Bobcat Goldthwait make banking investment decisions.