FORT WORTH -- Experts say there are some easy ways to ensure the money you're receiving is legitimate.

There's lots of advice out there on how to stay physically safe when you're buying and selling items using those popular exchange websites and apps.

But what about staying financially safe?

"It's just something you're going to have to know might happen, and be prepared for it," says Fort Worth Police Officer Tamara Valle.

It's a timely topic. This week, Fort Worth Police arrested 25-year-old Caitlyn Hernandez. After connecting on Craigslist, police say Hernandez met up with her victim at a gas station off Northeast Loop 820 and gave her two counterfeit $20 bills in exchange for a cell phone.

The police report says the victim only realized she'd been duped when she tried to deposit the money at her bank, and the teller said the bills were no good.

Valle says she doesn't know how many cases like this we've seen in recent months, but "I do know we get a lot of calls for simply counterfeit money," she says.

Greg Morse, CEO of Worthington National Bank in downtown Fort Worth, says that money often looks very real.

"You know, as sophisticated as the printing equipment is right now, they can get pretty accurate," Morse says. But he says there are easy ways to check and see if the money you're receiving is legitimate.

"The best way is feel," he says. Simply comparing the money to the feel of your own money should be a dead giveaway. He says also to look for strips on new bills.

"If you hold it up, it's like a hologram," Morse says.

Using water also helps; the ink on fake money can run. Or, meet your buyer at a bank and have the tellers run the cash through their machines that detect counterfeit money before you make the exchange.

"I don’t think there’s a bank around that would charge you to count your money, especially if it's your bank," Morse says.

"Just take those steps to be a little more proactive before you make the sale," Valle adds.

That way, you can leave both physically and financially sound.