On the cheapest airlines, such as Spirit, you have to pay even for a carry-on bag. (Dreamstime)

I don’t know about you, but I find daily life to be plenty confusing. So I don’t need to become even more dazed trying to figure out how much a plane ticket really costs. It wasn’t that long ago that you could just buy a ticket, feeling confident that it included everything you needed, from lunch to a nice, soft pillow.

But, nowadays, airlines are making record profits by charging us for everything, practically the air we breathe. This makes it hard to compare fares among carriers. Because, often, the seemingly cheapest fares really aren’t, once you factor in all the sneaky little fees they charge you along the way.

Now, here’s the rub: When you book your own ticket online, you really have to watch every single screen carefully, because some airlines will slap on extra fees you can miss unless you’re paying close attention. Sometimes you have to look for nearly microscopic boxes that have been checked for you, that add extras that cost money. Watch the cost of the ticket on every page, and if it goes up mysteriously, go back and use your best detective skills to figure out why.

For example, when I recently bought tickets to Mexico on Volaris, the computer program automatically charged me for choosing my own seats, and I had to go in and methodically uncheck each seat to make sure I wasn’t charged.

So, watch out for these sneaky fees.

1. Baggage fees

We all know about checked bag fees, which most airlines now impose except for Southwest. On the cheapest airlines, such as Spirit and Allegiant, you have to pay even for a carry-on bag, unless it’s a certain small size that will fit under the seat in front of you. I spent $40 at Costco on a small rolling suitcase that’s supposed to fit under airline seats, but I haven’t tested it out yet. One of these days I’m just going to wear all my clothes for the entire vacation on the plane at once, to avoid the fees.

2. Choose-your-own-seat fees

If you want to pick your seat, some airlines including Spirit, Volaris and Allegiant now charge you for any seat that you choose yourself, on the theory that you’ll otherwise be miserable with the seats they assign you. For example, some airlines will automatically assign you the last row in the plane, next to the toilets, just to spur you to pay more. In some cases, you have to line up to board before you can select an available seat.

3. Get-a-better-seat fees

Nowadays you can’t even sit where you like, because airlines are saving their best seats for people willing to pay for them. Want to sit in the bulkhead or exit row, where there’s extra legroom? That’ll cost you. Though if the airline hasn’t sold the seat by the flight date, you can ask to be moved there and sometimes they’ll oblige.

4. Priority boarding fees

Want to get on the plane ahead of everyone else? There’s a fee for that. I get it free now with my Delta Airlines credit card, so get out of my way.

5. Printing your boarding pass

Yeah, do it at home, lest the boarding pass gods charge you $3 to print it at the airport.

6. Change fees

You’ve probably experienced this already. God bless Southwest Airlines, which will let you cancel your advance ticket and bank the money in an account that you can use later to buy another flight. Southwest will also let you hop an earlier flight, if there’s room available. Otherwise, Lord help you if you have to change. Some airlines are charging you fees in advance to have the option of changing a name or flight later — this might be worthwhile, depending on how flexible you can be.

7. Travel insurance

Do not buy the travel insurance offered with the price of your ticket. If you want to insure your trip, go to InsureMyTrip.com and you’ll discover you can buy a much more comprehensive policy cheaper than the airline was offering you.

8. Food and drink

Yes, one of these days they’ll charge you for a cup of water. I flew my son home from Europe last summer on Norwegian Air and while it had ridiculously low fares, I ended up having to buy him meals in advance, because who can fly for 11 hours without eating?

9. Blankets and pillows

You’re not even going to have the option to buy these on most domestic flights these days, though they’re still free (if meager) on some international carriers. Bring your own little fleece one you bought at the 99 Cents Only store for 2 bucks, then you don’t have to pay $8 to buy the in-flight “comfort package” that includes them.

10. Movies

They used to be free to watch on long flights, but now you’ll pay a few bucks on many carriers. At least they often offer TV shows for free.

11. Headphones

You’ll sometimes have to pay $2-5 for a set, so bring them from home.

12. Restrooms

OK, I’m making that up. But it won’t surprise me if someday they start charging a potty fee.

How do you avoid the fees? Well, you can’t, entirely. But there are a few ways to reduce them.

1. Sign up for the airline’s frequent flier program — usually free

This shows brand loyalty, and that can count when the gate agents decide who gets the free perks. If there’s an open seat you want to move to, for example, or an upgrade available for free, you’re more likely to get it if you’re a member of the frequent flier club.

Also, it may be worth it to sign up for an airline’s credit card, if you can get miles and other freebies along with it. I signed up for a Delta Airlines card awhile back because it gave me an immediate 10 percent discount on the tickets I was buying to Costa Rica, priority boarding and free checked luggage for everyone on my ticket. Since I was bringing five people, total, that saved a bundle. The catch is that these cards tend to have high interest rates, so make sure you pay off any balance right away.

2. Bring your own food

Believe me, I know it’s hard in the last-minute scramble to the airport to think about bringing food, but you’ll save a fortune. You can’t bring liquids on the plane, but you can bring your own food. If you don’t have time to make it, there’s always Subway, and it’s going to cost a lot less in your neighborhood than at the airport.

3. Bring your laptop with movies

There are Redbox locations all over the country, and you can rent a DVD at one and drop it at another without penalty.

4. Be insistent

If an airline won’t let you sit next to your child unless you pay an extra fee for the privilege of choosing that seat, that is something to fight for. Being polite but never going away works with airlines. Delta changed the aircraft on me before we flew to Thailand and I lost our seat assignments, and they refused to promise me I could sit with my two then-small children. I didn’t get off the phone until I got a supervisor who understood the extreme misery that would result from another passenger sitting next to my unsupervised 8-year-old as he kicked and squirmed during a 13-hour flight.

5. Make a phone call

I find emails to be virtually useless when it comes to airlines. You need to talk to an actual person, preferably a supervisor.

The discouraging news is that with all this so-called “unbundling,” it’s very difficult to find the flight that is really the best value for you. All I can say is, get out your calculator. And good luck. May the force be with you.