My airline allowed me to print out a boarding pass and bypass check-in because I had no bags to check.

FORBES: J.C. Penney Faces Reality. Are You?

"I'd spend millions of dollars on the ground because you make the passenger happy... at check in and boarding, " said Mr Kotil.

BBC: Could airport hub capacity see UK lose out to rivals?

Joyce said the new partnership would benefit its frequent flyers in particular, with the airlines offering reciprocal access to tier status benefits, including end-to-end recognition of customers, lounge access and priority check-in and boarding.

CNN: Ailing Qantas announces alliance with Emirates

Use curbside check-in and print your boarding passes before you go to the airport.

CNN: readers share tales of terrible travel, pleasant surprises - CNN.com

Customers can check in for flights, print boarding passes, check bags and review flight status at delta.com.

ENGADGET: Delta expanding Gogo in-flight WiFi to select international flights beginning in 2013

Travellers should also consider printing out boarding passes ahead of time to speed up the check-in process, and should remember the rules about packing liquids and electronics in carry-on and hand luggage.

BBC: Navigating the London 2012 exodus

At the gate, agents can offer passenger the opportunity to check bags and, in return, offer earlier boarding.

FORBES: Will American's New Boarding Process Work? It Failed At Virgin America.

If they don't have a frequent-flier ID card, travelers check in online or at kiosks and get a bar code on a printed boarding pass or on a mobile phone, just like at other airlines.

WSJ: Flying Through the Airport