gramercy tavern hostess Julie Zeveloff/Business Insider
When you think about it, the travel industry is basically a booby trap just waiting for unwitting customers to screw up.

From hidden insurance fees on rental cars to the unexpected housecleaning tip added to your hotel bill, the costs can quickly escalate.

But none are quite as annoying as reservation cancellations. Hotels, car rental agencies and even restaurants sometimes have certain cancellation windows, and once you've missed the deadline, you're basically stuck -- unless you pay up.

SmarterTravel's Dana Continenza has a trick up her sleeve for travelers sly enough to try it out.

"This is a no-brainer, but it's something that many travelers don't think to do. If you missed the cancellation window for your hotel, restaurant, or car booking but can still change the reservation date free of charge, move your reservation back by several weeks or months," she writes. "Then call back to cancel with a different representative. Sneaky? Sure. But it works, and you'll never get stuck with a lousy cancellation fee again."

Unless the customer service agent digs through your reservation history to check whether you've changed before ( OpenTable is notorious for this), you'll be in the clear.

Canceling flights without getting slapped by a fee is much trickier. Your best bet is to either purchase trip insurance (covers death, illness, or cancellations due to weather), or pay with a credit card that comes with built-in trip protection. Be sure to review your policy.