I have to admit that I'm a fan of the movie Up in the air. That's the film where George Clooney plays an airline nomad sacking people for work and giving lectures about 'lean life'. There is a scene where he explains how he chooses the right security line, and his coworker accuses him of racism. "I'm like my mother, I stereotype", Clooney responds, after explaining that you should avoid people with children, old people and just stand behind Asian people because they are efficient and use slip on shoes.
One secret of moving around airports quickly is being agile. I always wonder why people take so much luggage that they are hardly capable of carrying it. I just don't understand. Why bother? In my closet, there's three lightweight cabin-size trolleys suited to the need of any holiday (not including camping - I don't camp, as you might already have expected). Two are four-wheeled, which allows you to easily move them around in a line at an airport. One is two-wheeled and only 40 cm high, which makes it suitable for max 4 day trips and smaller aircraft with ditto overhead bins.
First rule of travel hacking: always stay close to your luggage. You don't want to put your cabin trolley in the belly of the airplane where it might get lost, effectively robbing you of your luggage for your onward business class trip. Get on board first to secure room in the overhead bins, or pay to get the privilege to get your trolley on board. It should be light enough to put it in or get it out of the overhead bins without a significant exertion and a risk of injuring your fellow travellers. A trolley need not weigh more than 2 kg, and packed, 8 kg should be the maximum.
Another reason to keep your luggage close to you: you're more flexible. I paid 55 euro for a single ticket from Faro to Madrid via Lisbon instead of 110 euro for a single ticket from Faro to Lisbon - and the only reason this was possible is that I didn't check in my luggage. Then it wouldn't be as easy to leave Lisbon airport - which was the real destination of that trip.
Fancy a business class flight with your national carrier? It's usually cheaper to fly from a different country because indirect flights are cheaper than direct flights. So when I considered flying to the USA West Coast from Dublin via Amsterdam, I knew that it would be a lot easier to leave the fourth leg (Amsterdam - Dublin) if I only had carry on luggage. By the way, in business class, it's generally possible to carry two cabin size trolleys per person. That's the reason for having multiple ones in my closet.