General Strategies That Work
Earn Elite Loyalty Status
There's a reason they're called "loyalty programs"—the objective is to get you to concentrate your travel on the program's sponsor. And they often work well for those seeking free upgrades. Even if you don't travel enough to earn any special status, just belonging to a loyalty program can sometimes lead to an upgrade or other perks.
Enlist a Travel Agent
A travel agent who has clout with a supplier can sometimes score an upgrade for you that you couldn't otherwise score on your own.
No matter the circumstances, you can sometimes score an upgrade by just asking. But as loyalty programs become more systematic, the "just ask" strategy is fading rapidly, especially when it comes to airlines.