Sign at the beginning of the councourse:
Your Flight ===============>
<======== Your Luggage’s Fight
Biohazard Containment Room
A sign with two arrows in different directions. Damned If You Do - Damned If You Don’t
One of the sign posts like they did in Korea. Put labeled arrows on it pointing to different cities. You can associate the word confussion with it maybe.
A single sign pointing down. Land Down Under
Signs that say The wait from this point is so many minutes, and put the first one at the entrance with something like 4 hours.
Please Do Not Ride The Carousel
No Terrorist beyond This Point
“No Bagpipes Allowed”, with a silhouette of a bagpiper from the front with the requisite red circle with the line throut it.
Two signs appearing together and pointing the same way:
COMPLAINTS -->
EXIT -->
No Livestock Allowed on Aircraft
Please Do Not Feed or Taunt Flight Crew
No Durians Allowed
Dirigible Mooring Mast Area
Caution: Low-Flying Barnstormers
All Wing-Gremlins Must be on Leashes
Caution: Beward of Propwash, Jet Blast, Rotors, and Ornithopters
•Concorde—Departure Time: SERVICE SUSPENDED
•Lunar Rocket—Departure Time: SERVICE SUSPENDED
•Glorified Subsonic Trash-Hauler Crammed Full of Cowardly, Whining, Self-Important Ape-Creatures—Departure Time: 8:00pm.
“If your name appears on the Department of Homeland Security terrorist watch list, please inform the gate agent or portly TSA staffer.”
“Please keep your motherfucking snakes off of our motherfucking plane. Thank you!”
“In case of an emergency, you’ll probably be dead, so don’t bother listening to the flight attendant’s safety lecture.”
“Oceanic Airlines would like to inform you that your flight will almost certainly crash on a desert island where things that strain credulity will occur at least three times weekly. Enjoy your flight!”
“You may have this many weapons or bombs [handwritten here: ZERO] to ride this plane.”
“Complimentary pilot and copilot breathalyzer tests through this door.”
too little too late. We are having fun now 
“in case of an emergency landing, put your head between your knees and kiss your ass goodbye”
“do not pet or feed the pilot’s seeing-eye dog”
“no hypothetical treadmills beyond this point”
“do not moon the land crew until the plane is parked at the terminal and turns the seatbelt light off”