Some inexperienced travelers will beg for a free airline upgrade. They'll target people who have little chance of helping them -- and annoy those folks in the process. Flight attendants, for example, are busy with a variety of duties and typically don't make upgrade decisions. The same is true of gate attendants in all but the most pressing of situations. Make your inquiries at the ticket counter in the terminal.
There are "upgrade vouchers" for sale online in various places. Steer clear of these, because they are frequently fraudulent. The same is true of attempts to stamp your ticket with a "V.I.P" stamp that invites upgrades. This is not likely to do anything but result in embarrassment.
Another travel myth: simply sitting down in an empty first class seat late in the boarding process as if you belong there will result in a free upgrade by default. Don't count on it. These are expensive seats and the flight attendants watch them closely. If one is supposed to be empty, they will know it.
