The Chicago Tribune shook down a travel expert from American Express and uncovered ten dirty little secrets to getting deals from the airlines. Some highlights:

• Ever flown first-class? Me neither, but there are plenty of ways to do so without paying more. Last-minute tickets (especially international) as well as booking through travel agents are a couple ways where you won’t pay a penny more for the upgrade.

• Book over the holidays and save up to 20%. I guess the airlines are in a festive mood? Or they’re just trying to make up for the inevitable drop in sales post-holiday.

• Check out round-trip prices even if you’re flying one-way. Airlines hate booking one-way, so oftentimes you’ll slash the price by over half even if you’re not using the return ticket.