Cheat...Airline Passengers!
For the cattle car airlines, where you seat yourself according to boarding pass number, instead of assigned seating (e.g., Southwest Airlines): While at the bar before boarding your flight, dip the corner of a napkin in your drink (beer works well, a Bloody Mary even better). Unfolding the napkin as you walk onto the plane, place it on the seat next to you as you sit down. Now, close your eyes and suppress a smirk as the fellow cattle on your flight stop and see the open seat next to yours, as well as the apparent urine (or blood) stain that is apparently soaking into the napkin, and continue their journey towards the increasingly dismal ass end of the plane. Now you’ve nobody to fight with for the armrest, or, at least, you can be more selective on who shares the armrest.