Whether your trip is a globe-straddling epic or a simple capital city hop, being in your preferred seat can make all the difference. Fortunately, there's plenty of resources online to help with seat planning.
OK, if you're taking a comparatively brief trip like Sydney-Melbourne (a journey that runs more frequently than many suburban rail services), where you're sitting might not make much difference. But the longer the flight, the more being in a good location can help. Here's the issues to consider when planning (and booking) your flight.
Work out your own preferences
There's no such thing as a universally perfect seat (unless you're sitting in first class, in which case the sympathy levels for any complaining will already have pretty much disappeared). My own preferences work like this. For domestic flights, I want an aisle seat towards the front of the plane, so that I can make a speedy exit when we land. Because I usually travel only with hand luggage, I don't want the very first row of economy, since there's no under-seat storage space, and sometimes that's the only place you can fit your bag.
For international flights, I still want to be seated forward, but I want a window seat: I don't get out of my seat once I'm on board and I always aim to sleep, so I don't want somebody else next to me with a weak bladder to be clambering over me six times a night.
Many people take the reverse approach, choosing an aisle seat they can easily get up during the flight and stretch their legs. Others prefer sitting towards the back, buoyed by the theory that in the event of a crash they're more likely to live. Many people also like the concept of an exit-row seat for extra leg room, though that's often now an option you have to pay for, and you won't have any options for storing luggage within easy reach during take-off and landing.
Get in early
Once you know what kind of seat location you'd prefer, you can apply those rules when you book a flight. If you're a member of a frequent flyer program, then it's worth registering your preferences, since those will also get taken into account (especially if you're a higher-level member).
On some airlines (Jetstar being the prominent local example), you actually select your seat when you make an online booking. Others let you select your seat if you check in online, so make sure you check in as early as possible ahead of your flight (24 hours ahead for Qantas and Virgin). If you happen to use a travel agent, you may also find that your seats can be picked at the time of booking.
Check your own airlines' site
Seating options vary considerably between planes and airlines. While general principles like "window forward" will work on any flight, you may want to have a better idea of the specific layout on a plane (so that, for instance, you're not sitting near a high-traffic area like the toilets).
Your first port of call should be your airlines' own site, to get an idea of what options they offer. This information isn't always super-helpful: for instance, even if you click on a seating link for a specific flight booking with Qantas, you'll be presented with a range of different seating configurations possible with that plane, and no guidance as to which one actually applies in your case. But it's a start.
Check out specialist seating sites
For a more detailed discussion of the pros and cons of particular seating locations, there are a bunch of sites which include airline-specific seating plans for common plane models. The best-known are SeatGuru and SeatExpert. If you're only looking at business class options, Flatseats offers reviews of individual seats.
Realise it won't always work
Even after all this planning, sometimes your seating plans will go awry. Most airlines will present you with terms and conditions which note that seating allocations can change, and this isn't just idle chatter: I've had services switch from a 737 to an A380 on minimal notice. (That particular change was actually an improvement, but that's not always the case.) And sometimes your seat turns out to have problems like non-functional power or in-seat entertainment.
Don't go into a frenzy of abuse if this happens; it's very unlikely to help your case. But do send a letter to the airline afterwards and see if you can score up some compensation.
Got your own seating planning secret? Share it in the comments.
Lifehacker Australia editor Angus Kidman still isn't entirely convinced of the virtues of exit rows. His Road Worrier column, looking at technology and organising tips for travellers, appears each week on Lifehacker.