Useful Tips for Inexperienced (and experienced) Airline Passengers
I've flown on commercial airlines hundreds of times. Based on that experience, here are some tips for passengers who don't travel much, and for experienced flyers who don't pay much attention. They'll help at every step of your journey. They'll also help you not be that passenger who slows everyone else down.
1. Have your shit together - Before you leave for the airport, check to make sure your ID is easily accessible and your boarding pass is, as well, if you printed it out beforehand (you should). When packing, don't put all those bottles of shampoo and other vanity products in your carry-on. Put them in checked bags or leave them at home. They sell that stuff where you're going, too.
2. Dress to fly - Wear shoes that are easy to remove. You'll have to remove them unless you're a TSA pre-check passenger. It's a pain in the ass to have to bend over and untie your shoes. Wear slip-ons and you'll be much happier. Also, wear a light jacket with big pockets that can be closed with a button or zipper, even if it's warm. As you approach the security screening, move the junk in your pockets (all of it) into the pockets of the jacket while you're waiting in the long security line. If you're wearing a bunch of jewelry (why?), put that in the pockets, too. Then, when you approach the screening area you can remove and fold your jacket and put it in the bin. Don't leave anything in your pockets. Put it all in your jacket pockets before you get through the line. That jacket, folded up, also makes a great pillow during the flight. Alternatively, you can stash that junk in an outside pocket of a carry-on.
3. Show up early at the airport - Seriously. You're going to enjoy your trip a lot more if you show up early and have plenty of time to check in, check your luggage and get through security. It's a lot more relaxing to sit at the boarding gate with your mocha latte until it's time to get on the plane than it is to run through the terminal at the last minute.
4. Check your bag outside the terminal - If you printed your boarding pass at home (another reason you should), don't go inside and stand in line to check your bag in. If there's a redcap station outside, do it there. Give the nice person who checks you in a $5 tip. It's worth it. Once your bag is checked, you're done, and can go straight to the security screening. This saves time and hassle.
5. Get ready for the TSA screening - You'll need your boarding pass and ID immediately available. Hold them in your hand or put them in a shirt pocket or somewhere that's instantly accessible. Don't wait until the last second to fish your ID out of your purse or wallet or to dig out your boarding pass from your carry-on. See #2 for instructions about what to do with all the crap in your pockets. If you have a belly cover as a belt-buckle, remove your belt and put it, rolled-up, in your jacket pocket, too.
6. Read stuff and listen to announcements - When you get to the TSA screening area, look around and read those signs everyone ignores. Review your preparations and make sure you've dealt with your liquids by putting them in small ziplock bags. Listen to the PA system announcements closely. They may give you information you need. Pay attention to your surroundings and learn from the passengers ahead of you, as well. As the line moves ahead, please move along with it. Don't delay others.
7. Follow directions given by TSA people - Smile and hand your boarding pass and ID, face-up, to the nice person at the desk and listen to that person, who may ask you a question or two and will tell you what to do next. Don't get distracted. This will help you get through security faster. Note: If you have an internal joint replacement, tell the nice person at the desk about it. That will save time, since he or she will be able to instruct you on what you need to do. If you don't, you may have to do things twice, and that wastes time.
8. Be efficient at the X-ray conveyor - Those bins? Use them. Use as many as you need. If you have a laptop, take it out of your bag or carry-on and put it by itself in a bin. Put your shoes in a bin and fold your jacket (full of the junk in your pockets) and put it on top of your shoes. Put any small junk you're carrying in a bin, too. Put your carry-on on the conveyor, along with your purse and any other large junk you're carrying. If necessary, push the entire lot forward until everything reaches the moving belt. Then step over to the next station.
9. Wait patiently for the TSA person to tell you what to do - Go through the metal detector or scanner, following whatever instructions you are given. Look at the diagram inside the x-ray thing. Do what it shows. Stand still. Then follow the next instructions from the TSA person. If you are asked to step over and be patted down, just do it. You're not going to argue your way out of it, so just do it. Usually, it will only involve checking some specific area that was indicated by the scanner. It will only take a minute or two. If there are other issues, listen and follow whatever instructions you are given. There's no point in arguing. That will only delay the process, and you will never win such an argument.
10. Pick up all your junk from the x-ray conveyor - Don't stand there after you do this. Move on, so the next person can pick up his or her junk. Carry it over to the nice, uncomfortable seats outside of the security area and reassemble yourself there. Always move promptly from one area to the next, to avoid annoying everyone around you.
11. Before going to the gate indicated on your ticket, check the flight display near security - You might just discover that your gate has been changed. It happens all the time. If you go to the wrong gate and then have to go to the right gate, you'll waste more time. However, do go directly to your assigned gate. Do that before browsing through the shops, buying magazines, sandwiches, candy bars and other junk to take on the plane. You want to find your gate before doing that, especially in an unfamiliar airport.
12. While waiting in the gate area, look once again at the flight number on your ticket - Remember it. Listen to PA announcements, and if you hear your flight number, pay attention. You might learn something interesting. If you have a boarding pass, which you clearly do at this point, you don't need to go up to the gate counter. You have a seat. Don't worry. Amuse yourself by watching the growing crowd or play with your cell phone or other devices. But keep listening.
13. When boarding begins, listen even closer to the announcements - Do what the nice airline people ask. If you're in Zone 5, don't line up to board when Zone 3 is called, for example. You'll just slow everyone down. Sit down and be comfortable. Then, when the zone or whatever before yours is called, wait until the line grows and then stand up and move up near the back of the line, so you'll be there early when it's your turn. Don't attempt to board until it's your turn. Don't wait until the last minute before boarding. Board when your group or zone is called. Otherwise, you'll just waste your time and everyone else's.
14. As you board the plane, have a plan for your carry-on - If it must go into the overhead bins, then hoist it up there efficiently when you reach your row. Don't suddenly decide that you need something in there. You should have thought of that earlier. If your carry-on will fit under the seat in front of you (recommended), stow it there, not in the overhead bins. Note: bags under your seat are much, much easier when you arrive. You just pull them out and walk on. Leave room for others. Take your seat immediately. Sit in your assigned seat, not the one you'd prefer. Otherwise you'll slow things down when the person who has the seat you took shows up.
15. Once seated, listen to announcements from the flight crew - follow their instructions. Don't wait to find out how to put your cell phone in airline mode until they announce that you need to do that. In fact, anticipate as much as you can. Don't be that person who insists on talking on their phone until a flight attendant comes over and demands that it be shut off. That delays things. Don't delay things.
16. Once the flight is in the air, deal with stuff - The drink and snack cart will eventually get to your row. You probably don't really need that thing you forgot to take out of your carry-on in the overhead bin. Relax, and try to be as comfortable as you can, and let the time pass. Don't start a conversation with the passenger next to you if he or she is reading a book or doing something else. If you don't want a conversation, read a book or do something else. Don't decide that you need to use the toilet while the snack and drink carts are moving in the aisles. Wait until they're past you. It's just not nice to make them back up so you can go potty. Really.
17. When the plane lands, gather all your junk together - Wait for your turn to deplane. Everyone will get off the plane. You will get off the plane, too. There's no way to speed things up, so sit there and relax a few more minutes. Listen for the announcement of which luggage carousel is assigned to your flight. When it's your row's turn, just get up and go. If you did store a bag overhead, please be careful not to knock someone in the head when you pull it out of the bin. Finally, as you enter the terminal, keep walking. Don't stop right in front of the entry door to get your bearings. That will only delay all the people behind you, and isn't that annoying when it happens to you? Just walk briskly on until you get to the main aisle. Then look to see which way you need to go.
I hope this information and these tips help you with your next airline trip. Who knows? I might be on it, too.
= new reply since forum marked as read
BTW, why do men have nipples in the first place? Proof of evolution, I guess. 
Check luggage restrictions (checked & carry-on restrictions ahead of time)... Measure your carry on. (DON'T assume that allowed PERSONAL item can be another full sized carry-on-- IT CAN'T. It is meant to be a SMALL purse, camera bag, diaper bag--not a gargantuan tote bag, duffle bag or 40 + pound laptop bag--that can be your primary carry-on but not your personal item for those airlines that allow) Pack and then remove at least half of it. An over-filled bag may well no longer meet size restrictions but worse, render it so heavy you can't or can barely hoist it into the overhead bin, while putting all the travelers seated below at risk for concussion as you try. Travel was once a fashionable experience (decades ago). No longer. If you must renew your look EVERY day, consider scarves (or ties for the guys). Wear a monochromatic wardrobe that mixes/matches with no fuss Otherwise be prepared to haul all that extra stuff (and pay for) the appropriate number of checked bags.
I do strongly disagree on not carrying the allowed quart bag of toiletries. I'd bet most women here might agree, that a lot of what you can pay obscene prices to replace at the airport on landing or in the hotel to try to substitute is going to make your stay MISERABLE. Just stock up on the travel sizes or make your own ahead of time. Read the allowances and FOLLOW them. Many carry-ons now have a convenient pocket just for the toiletries, allowing easy access for the screeners. Worth it.
IMHO, the single most important thing to carry (i.e., not the blow-up pillow or the folding footrest or all that other crap)... are NOISE Cancelling headphones with your cellphone/ipad/ipod/ or old time mp3 player stocked with your favorite music. Chosen carefully, it can keep you sane when all about you is chaos (even with very unhappy infants crying all around you). That and some deep breathing exercises can you you through about ANYTHING>
Then prepare to use all that wasted waiting time, precisely calculating the comparative $$ and time cost of traveling by car or any other means next time. While it might not be a practical alternative, the exercise will be cathartic. 
Sound blocking/cancelling headphones/plugs, or just plain old foam earplugs and an eye mask. I can check into another dimension of space after sitting down. It's like Tommy:
wherever I go.
But even knowing my flight is cancelled is a big help.
Beat thel rush. 🤗
I'm sure your tips will help many people.
Terminal C is just fine. Quite nice, actually..
It's A and B that suck. If I ever had more than an hour in either one of those I hop the shuttle over to C.. 
Of course the Wi-Fi in all of them blows.... Boingo Spot or whatever that ting is...
jeesh... in, oh say Incheon.. you're off the plane and you have FASST WI-FI like 100+ Mbs 
It even works in the underground train that take you to the main terminal...
Pretty much the case in the civilized world as well.. Tokyo, Honk Kong, Singapore, Amsterdam, Oslo, Frankfort, Lisbon.. St Petersburg even..
I follow all these tips! 
In general, you're not allowed to walk around the airport with open containers. Alcohol consumption is typically reserved to restaurant premises in the terminal that have alcohol permits. That being said... nobody's going to think twice about someone drinking what looks like pop or juice walking around the terminal.
The federal laws governing drinking ON PLANES stipulates you can only drink alcoholic beverages "served to you by an in-flight attendant". Basically, if you want to be on the right side of the law, simply give the bottles to an attendant and have them give it back to you... so there, they've "served" it to you. Or you could retrieve it from your pocket and pour it yourself after they walk away because nobody's going to care.
As always, getting visibly intoxicated or sloppy in an airport or on a plane is a really BAD idea.
Sidenote on public drinking... In college, I used to walk to (and sit in) class while drinking white Russians or irish coffee from a clear starbucks frappuccino glass. I'm sure everyone assumed it was just iced coffee. 
I used to fly a lot. Less now.
I try to watch what I eat and drink in the days preceding my flight. I make sure I'm fully hydrated for a few days before flying, and then I don't overdo liquids in the hours preceding my flight so I don't have to be too concerned about nature's call on the plane.
As for what I eat, I don't want to have to deal with any digestive issues when traveling. I'm not going to be the one responsible for the "silent but deadly" noxious fumes. 
