You've probably seen the offers hundreds of times. Sign up for a specific airline rewards card and get tens of thousands of miles, plus one mile for every dollar spent.
According to Zaraysky, these kinds of offers can be gold mines for savvy travelers, especially if the issuer waives the first year's fee.
"I accrue so many miles because I play the games offered by the airlines," she says. "Each airline has its own credit card that it wants its customers to use, (and) you get a 15,000- or 21,000-mile bonus when you sign up for the credit card."
Still, it's important to keep your perspective on these offers, Zaraysky says. Travelers need to be able to pay their bills on time every month. Otherwise, the extra miles won't make up for the hit your credit score takes.