You can generally save by flying on Monday, Tuesday, Wednesday, or Saturday. Shifting airports, say, arriving in Rome rather than Florence, can also yield savings even after accounting for the cost of a ride by train or car to your desired destination. Flying at less desired time of day or year (September rather than August) can also result in lower fares.

Vivek Prakash/Reuters
A Singapore Airlines (SIA) Boeing 777 aircraft taxis past a parked aircraft at Changi Airport in Singapore, in this file photo taken May 13, 2009.