A travel-related article titled "Beware the Fees on Europe's Budget Airlines" was published this week in The New York Times.
Although addressed to a US readership, it might be helpful for other overseas visitors to Ireland and elsewhere in Europe who are considering using a low-cost airline for travel within Europe.
Baggage limits in terms of weight and dimensions; check-in rules; the importance of printing boarding cards in advance; using a credit card or a debit card; travel with a baby; various administrative fees are all dealt with in the article.
British Airways and Lufthansa get positive mention for more generous luggage allowances and if you want to avoid all the hassles of flying, taking a ferry is another viable option.
You may have to register with the NYT (free) to read the article in full.
One additional point not mentioned in the article for anyone traveling with Ryanair, (maybe other airlines?) on a passport from a country not in the European Union (EU) or the European Economic Area (EEA) is the necessity to have all your papers and boarding pass stamped at the Ryanair desk at the airport, ahead of going to the Security Line:
See General terms and conditions of Carriage on Ryanair's web site:
The relevant article is at 6.4:
6.4 All non-EU/EEA citizens must have their travel documents checked and Boarding Pass stamped at our Visa/Document Check Desk before going through airport security.