Having spent the last few years traveling for 200+ days a year I have picked up a few tricks. Here is a few quickly scribbled down on my blackberry in Copenhagen airport :)

• - Use earplugs or in-ear headphones when ever you move into the airport. Reducing all the sounds makes the trip through crowds less stressful.
• - The trick to win the battle of the armrest is to place your elbow all the way on the back of the armrest. Then slowly apply more and more pressure as you squeeze the arm of person next to you of the armrest. Beware of people with prosthetic arms. Can be pretty embarrassing....
• - Always check www.seatguru.com when checking in online. Here you can find the best tips on what seats to book in the different type of planes.
• - Female immigration officers are almost always the quickest, so pick their line even if the cue is longer.
• - if you have a crappy seat - tell the personal that you are willing to operate a security exit. Airlines are required to have an adult sitting in those seats and more often than not someone has booked online and traveling with their kids. They will be asked to be moved and the crew will ask someone else. If you have asked before they are very likely to move you there.
• - if someone want to talk to you and you just want to sit and read - put on your headsets. Even if they are not connected - its the best and sometimes the only way to get people to shut up
• - ask what the daily upgrade price is when you check in. Sometimes you can get into one class higher for a small fee. On long hauls its worth it.
• - the best way to get free upgrades (beside being a gold card holder) is to board late. airlines seems to do last minute changes and by boarding late it seems to improve your changes. (don't know if this is actually true - but it has worked for me most times). Please note that on short haul flights - you don't want to risk this. As you want to get in early to claim the overhead space for your carry own :)
• - best way to fall a sleep is to listen to some breathing exercises. On some airlines (e.g. virgin) they have it as one of their channels. It sounds weird - but its really worth it.
• - if a loved one wants to know your travel plans use http://flightaware.com/ or http://www.flightstats.com. Both offers very detailed information about your flight. Sometimes you know more about whats going on used that site than what they tell you in the plane.
• - if you go to e.g. the US a lot, then buy a local pay as you go sim card and place that in your secondary phone. you will save a ton of cash on roaming and data. My primary phone is a blackberry (with my uk number), my secondary phone is an iPhone. In the US i have bought a Att GoPhone pay as you go. I pay 3 dollars a day for all I can talk and $20 for 100mb of data. If you are there more than a day or two you can really save a lot of money.
• - if you sit next to a smelly person - you can minimize the discomfort by pointing the airstream above you towards your shoulder. It will soften the smell by blowing it away to you. (can also be used if you are a bit smelly yourself :)
• - I have found tablethotel.com to be a pretty consistent service for good value nice hotels. Its not the cheapest - but always have a pretty good value for money.
• - get a kindle and forward all the stuff you never get to read to it.
• - its okay to be annoyed with people who stand too close to the luggage belt.

Thats all I can come up with right now. Safe travels and please add tips to the comments. See you in transit :)