Check in late – if the flight is full, you’re more likely to get moved up a class.
Dress well – those in business attire stand more chance.
Don’t ask – if you dare to ask, it’s hardly ever given!
Join the family – frequent flyer members are often the first to be upgraded.
Take a hit – if the flight is full and they ask for people to stand down – take it if you don’t HAVE to be at your destination at a specific time. You’ll enjoy an extra night in the town you’re visiting, at their expense, and very often you’re upgraded on the next flight … AND there’s often cash compensation, too!