Once, they overbooked economy, and needed to move somebody to first class to make room.
We saw the cabin attendant walking down the aisle with a list, and we happened to belong to the frequent flyers club and were dressed nicely, so we got bumped up to first class.
I think the dressed nicely was key. One of us in a jacket…. A step up from business casual.
I’m always nice to the cabin crew.
If you have a tight connection between flights, ask the crew on the first leg if they know what gate the connecting flight departs from. It can make the difference between catching a flight and cooling your heels for hours.
Avoid the last row of seats. They can’t recline. The seats by the emergency exit over the wing have more leg room, but you have to be physically able to remove the exit door in case of emergency.