Holiday time means lots of travelers with lots of baggage and lots of questions. If your luggage could talk, it would pass along some of these useful, money-saving tips. Since it can't, allow me.
1. Almost all bags cost something
Sometime in 2015, JetBlue will quit offering free checked-bags. Does this mean Southwest will always be the best deal because it'll be the only airline with free bags? No. Sometimes Southwest will be the cheapest, and sometimes it will cost the same or more than the competition (even when factoring in free bags). No airline always has the best deals so shoppers must compare fares then add (or subtract) fees to find the real bottom line.
2. Watch out for holiday surcharges
Spirit is adding a $2 holiday surcharge to all checked-bags for Christmas and New Year's flights. It's not only though; European discounters like Ryanair are notorious for multiple seasonal fee adjustments.
3. Tiny = free
You know how to save $50 fast? Use a carry-on bag, except if flying Allegiant, Frontier or Spirit since they charge fees for hand luggage. But even these carriers make an exception for very small bags; they are free provided they can be shoved under a seat and stay there throughout the flight.
4. Bags will be fat-shamed
Overweight bags fees may shock you. Pack too much and you could pay dearly.
Checked-bags: American Airlines charges $100 for any bag over 50 lbs. and $200 for bags over 70 lbs. Other legacy airlines have a similar fee structure but weight limits vary from carrier to carrier; Allegiant, for example, calls a bag overweight at 41 lbs. Know the limits and stay within them.
Carry-on bags: Smaller bags sometimes have weight allowances, too. Hawaiian Airlines limits hand luggage to 25 lbs. or it goes into cargo; discounter Ryanair allows 22 lbs. and if you go over, the penalty/fee is a breathtaking $78.
5. Size matters
Just as weight matters, so does dimension. If a checked-bag is considered oversize, it will cost $200 on United and that's in addition to the standard $25 checked-bag fee.
The typical U.S. checked-bag size allowance is 62 inches total (height+width+length) but oversize boundaries can and do vary by airline, and this is especially true for international carriers.
Final tip: Watch out for the baggage police! Airline reps seem to be out in force for the holidays, measuring bags (or at least eyeballing them) for on-the-spot decisions about weight and size. It's happened to me and despite the fact that my carry-on was a legitimate size and not overweight, I was forced to give it up. Where baggage police are concerned, there is no appeal.