While being bumped from a flight is rare, the following tips will keep you out of the gate agent's crosshairs the next time they are selecting passengers to give the boot.
1. Check in 24 hours before your flight
This is the easiest way to avoid being bumped. Many times the last passengers to check-in are the first to be bumped from the flight. Avoid checking in at the airport and do it 24 hours before online. You snooze, you lose.
2. Don't be the last to board
Be at the airport well ahead of schedule and board when your number is called. Having a credit card from the airline you are flying also typically lets you board in a higher priority group. Don't be in the last group where you could get bumped or more likely have no overhead bin space available.
3. Seat assignment
Not having a seat assignment could lead to you being singled out for being bumped. I will admit I tend to roll the dice to save money on flights by not paying to assign a seat. It's a small risk I'm willing to accept.
4. Avoid peak travel times
Spring break and holidays are the worst times to fly for a variety of reasons, including being stuck in an oversold position. Airports are slowest midweek (Tuesday – Wednesday), which is when I love to fly and it definitely increases my chances of an elite upgrade.
5. Fly Business or First class
Ya ya I know this isn't the cheapest option, but it is highly unlikely you will be bumped if you are are in a premium cabin. You might be surprised at how cheap domestic first class flights have gotten. Always check first or business class prices before purchasing your economy ticket.
6. Enroll in the airlines frequent flier program
Having elite status with an airline will greatly improve your chances of staying on your next flight. Will simply having a frequent flier number with no status help you out? Depends on the airline, but it sure can't hurt.
If I don't have any immediate plans at my destination, I absolutely love being bumped or volunteering to take the next flight. You can get anywhere between $200 and $1,000 typically. I usually don't bite until the offer goes above $400, but it all depends on how long I have to wait for the next flight. The airline will usually offer you a voucher or gift card but it's important to ask what form of compensation they are offering. Cold hard cash is better than a Delta or Best Buy gift card. Also ask when the voucher or gift card expires as you don't want to receive something you won't be able to use.
My last bit of advice is to be nice to the gate agents. They have a thankless job and a smile and thank you goes a long way towards getting you what you want.