The following are some tips worth knowing:

Packing light will make for a more enjoyable trip.  The key is to take only what you can easily carry.
Focus on collecting as many air miles as possible with as few airlines as possible, thereby maximizing your miles with those airlines.  Signing up for an airline’s credit card adds miles, all of which can be used for free tickets, upgrades, hotel stays, and now often purchase merchandise for free.
Finding the cheapest flights often requires being flexible.  Frequently, by flying into or out of a close by city (that is close to your origination or destination) you can save big bucks. 
If you are traveling to Europe, you may find the cheapest route to your destination is to fly to the cheapest city in Europe (regardless of your ultimate destination) and then flying with budget airlines Ryanair or Easy Jet which offer many very cheap connections.
Build in extra time around scheduled plans so that you reduce the likelihood that one delay will result in a series of missed connections and cancelled hotel reservation that may be non-cancellable and paid for in advance.
Always pack something to read or do in your carry-on luggage so that if there is an unexpected delay you have something to keep yourself occupied.
The unexpected often occurs on a trip.  Have back up plans ready.  Have bus directions in case there is a taxi strike.  Have the address and phone number of another hotel in case your hotel is overbooked.
Being friendly to airport staff can go a long way.  By establishing a positive rapport, you increase your chances of being given an upgrade, directed to a special check in line, or other perks.  This is true when interacting with all service people.  The friendlier you are the more likelihood you will be treated better.