I enjoyed David Pogue's tips for air traveling efficiency, but he left off the list my absolute No. 1 tip for anyone who flies for work remotely frequently—sign up for a frequent flier program and pay attention to it!
This seems perhaps too obvious to make a lot of travel advice lists. But in my experience a lot of people don't actually do it. Now for many people it's not going to make a big difference. But for some of you it will, and it's really worth a little bit of your time. It's not really about the free (or free-ish) tickets you can accrue with miles either, it's about seeing if you fly often enough on any one airline alliance to obtain some form of elite status.
One of the main reasons why the quality of the air travel customer experience is so low is that most people fly very infrequently and yet these infrequent fliers combine to be a large share of the market for air travel. But if you don't fly much, then it's not really worth it to the airline to invest much in making you like them. If you get even the lowest-tier of status (I have no experience with the higher tiers, but I imagine they just bathe you in champagne) you end up with a much higher-end product typically featuring more comfortable seats ("economy plus" United calls them) and shorter lines ("premiere access"). It turns out that for all the dozens of things people moan about air travel, if you can get extra legroom and shorter lines it's suddenly much easier to appreciate the miracle of flight. The various customer service people you interact with if something goes wrong will also be nicer to you.
Of course this advice is useless to you if you don't fly often enough to qualify or if the routes you need to fly aren't convenient to all bunch together on one airline (it helps to live near an airline hub!) But the fact is that this is really the only air travel tip that matters. The high-quality experience is reserved for the high-volume customers. If you're not a high-volume customer, you're screwed. But if you are a high-volume customer and you're failing to signal that because your travel is divided across airlines, then you're losing out. Find the alliance with the most flights to your city, sign up, and make sure to fly them.