If your flight is cancelled you should just 'sit it out' in the airport, consumer journalist Sinead Ryan has said.
The host of The Home Show on Newstalk said carriers are obliged to reroute or refund you under EU law.
She told Lunchtime Live the best thing people can do is wait.
"I took a Ryanair flight myself over the weekend, and on their check-in [desk] when you go to the gate, there's a big notice up saying: 'If the flight is delayed more than two hours or cancelled, talk to us about getting an email about your rights'," she said.
"They have to do that, that's the law.
"My advice is always sit it out and wait it out.
"At least if you say, 'Reroute me' - and you sit at the gate and you wait - they will have to sort it.
"There's no question that they'll have to do that.
"Then if you, say, take the refund then you keep your reasonable expenses.
"Keep all your receipts for everything you had to do [and] apply to the airline.
"If they refuse get on to flightrights.ie, fill out the form and let them handle it".
Booking through an OTA
Sinead also said people booking through an online travel agent (OTA) should be careful.
Responding to a listener who booked a flight through trip.com, Sinead explained: "This is not the same as a travel agent like Cassidy's or Budget Travel, which are bonded in Ireland.
"An online travel agent is when you go into somewhere like Skyscanner, and you get all the fares at the side.
"Expedia, Kayak, LoveHolidays - all that - and you click on one of them and book it.
"The companies exist, they're legitimate, there's nothing wrong with them - but when something goes wrong, they are rarely based in Ireland, or indeed in Europe.
"Trip.com is based in Singapore: you are going to have problems from the get-go getting stuff back that might exist under EU legislation, but doesn't necessarily exist over there.
"You might have saved €20 on the flight, but this is why it's not a great idea," she added.
