Oh, wait. Forget all that if you'll be traveling on Spirit or Allegiant. Both now have carry-on bag fees that can cost as much as $45 each way (if you check your bag at the gate). You absolutely have to take a sizeable suitcase? Then fly JetBlue or Southwest, the lone domestic airlines that'll still give you checked bags for free.
If you must check a bag and pay a fee, then fill up just one big 50-pounder for the entire family but don't cross over that magical poundage mark. On some airlines, the fee for an overweight bag is twice the price of checking a second suitcase.
4. Failure to follow TSA rules.
You might hate those airport security rules, but don't make a stand at the start of a trip or you could face major delays (or even get a cup of coffee hurled at you). You can always fill out a complaint form when you get home. Meantime, forget about bringing suntan lotion if the tube is more than 3.4 ounces. The same holds true for self-tanner if you'll be staying indoors. Bottles of wine are OK in checked bags but if your suitcase isn't hard-shelled, you might want to think twice about that.
And no weapons, please. TSA officers confiscated 24 loaded guns in a single week last month. In nearly every case, it's because the traveler "forgot" about it. The good news: You can take your iPad along without removing it from its case (that is, unless a TSA officer insists on having a closer look).
5. Failure to plan on delays
Summer thunderstorms in a single large city can easily snarl air traffic from coast to coast (case in point: the recent hail in Dallas that resulted in delays for days). It's always possible to get stuck in the airport for a while, so plan accordingly, especially if traveling with kids. Make sure you have fresh batteries and chargers with you, and something to keep the kids (and you) occupied with.
Air travel can feel like a maze -- with all those twists and turns and frustrations that await you -- so prepare like a seasoned traveler for any eventuality. That way, at your next dinner party, you'll be the one listening to the latest airline horror story, and not the poor soul recounting the tale.