When flying, two truths weigh heavy on the traveler’s soul. The first: Checking a bag is expensive and annoying. The second: Planes have a finite amount of overhead bin space. Fail to score some of that space, and you’re doomed to baggage claim purgatory.

These truths ignite within us a gnawing sense of scarcity. They turn typically levelheaded people who don’t mind waiting their turn at, say, Starbucks into the type to elbow their way into the anxious swarm crowding the gate before takeoff. “Space,” they chant, like suitcase-rolling zombies. “Spaaaaace.”

Okay, maybe it’s not that bad. But the limited overhead bin situation can bring out the worst in people. Once you’re on board, it can feel like a race to find your seat and stash your stuff. “It’s a Tetris game,” says flight attendant Sabrina Schaller.

To prepare you for your next round, here are the unofficial rules for navigating the overhead bins.

1. Pack with the plane in mind

Let’s start with the most basic rule of all: If you’re planning to travel with a carry-on bag, make sure it’s going to fit on the plane. Schaller recommends going on your carrier’s website and seeing what measurements they allow. Next, stick to your airline’s allotted number of bags (this can depend on your ticket type), and be warned that the industry is getting tougher on personal items. Before you board, consolidate your bags to meet their criteria; it’s usually two per customer. Lastly, don’t hold up the boarding process by attempting that consolidation on the plane.

2. Keep your valuables with you

While you’re consolidating, make sure your valuables (jewelry, medications, Tamagotchi) are with you in that “personal item” versus the bag meant for the bin. This protects you in case you’re asked to gate-check, or the rare misfortune someone walks off with your luggage. “Anything expensive is always in my backpack because I know it goes under the seat with me,” Schaller says.

3. Don’t be a bin hog

The land of the overhead bin is not yours to claim a la manifest destiny. It’s a community space for everyone to share, says Heather Wiese, a Dallas-based etiquette expert. Remember the rules: Overhead compartments are primarily for carry-ons that don’t fit in under the seat. Everything else is extra, and should be stored up top only when everyone has boarded and at least attempted to store those bigger bags first. Then you can stake more square footage.

4. Use a bin near or before your seat

Make your life easier by putting your bag in the overhead bin above or around your seat. It’s not a crisis, but you don’t want to fight the flow of traffic to get your bag once the plane lands. Of course, this rule goes out the window if you board and there’s no space near you; in that case, Godspeed. Then wait until others have deplaned in the rows you’re backtracking past before going for your unfortunately-placed belongings.

5. Don’t force a bag that’s too big

Even if you sneak a real honker of a bag past the gate agent, you still have to find a place for your contraband once you’re on the plane. That could result in:

1. Wrestling your luggage into the bin

2. Getting scolded by a flight attendant

3. Having to check your too-big bag after all

4. All of the above.

Even worse than the embarrassment, going through this process slows down boarding. “When the bag is too big, it delays us getting the flight out on time . . . that’s the whole goal,” says Miami-based flight attendant Trey Antwan.

6. Make sure the bin closes before you walk away

Before you take your seat, ask yourself, “Will the bin close over my bag?” Better yet, just do a quick check. Maybe you goofed and put your bag in a weird way (or you broke the rules and brought a humongous bag), but this step will help correct the error so the flight attendant doesn’t have to.

7. Don’t expect help from a flight attendant

Flight attendants follow the motto: “You pack it, you stack it.” It’s simply not their job to help you with your bag. Some may be allowed to do so — and inclined to help older passengers or those with disabilities — but they’re not required to by airline policy, as it could result in injury. If it’s too heavy for you and for them, the bag’s getting checked.

8. Ask before moving someone’s stuff

Some people handle the stress of travel better than others. Because you never know what’ll be the straw that breaks the camel’s back, err on the side of caution and keep to yourself. That includes baggage handling. “I have definitely been on flights where fights are broken out because someone has touched someone else’s bag, and we have deplaned,” says Clarissa Laskey of the travel blog Passports and Parenting. Antwan has also seen conflict erupt from bag-moving, so if you do need to do some bin rearranging, give the owner a heads-up or ask a flight attendant for assistance.

9. Don’t freak out if you have to check your bag

Sometimes, even when you’ve been militant about packing your carry-on per the airline’s rules, you’ll be asked to gate-check your bag. While that reality is out of your control, how you react is entirely up to you. Antwan says the typical response from travelers is negative. “They want to argue, or they don’t believe us . . . people get pretty mad,” he says. His response: “I’m not checking your bag because I’m being mean, I’m checking it because it literally won’t fit.”

10. Save jackets for last

Accoutrements like jackets and puffy winter coats aren’t automatically deigned space in the overhead bin. You can put them up there as a treat, only if there is room after the rest of the plane has stored their carry-ons. The same goes for your other personal items, like laptop bags, fanny packs, animal skulls and airport shopping hauls.

11. Offer to help your fellow passengers

Your stuff is stashed, you’re buckled up and ready for takeoff. Down the aisle comes someone struggling with a bag. Like flight attendants, you’re not required to step in and help. But if you’re willing and able, do the struggler a solid and ask if they’d like a hand. Bonnie Tsai, founder and director of Beyond Etiquette, says not only is this an act of kindness, it also helps speed up boarding. Just make sure you’re ready to take no for an answer, Wiese adds, and that you don’t make a big deal of why you’re helping (i.e. pointing out that they’re elderly or appear frail, etc.).

12. Don’t abuse bin access

Once your bag’s up there, consider it gone until the end of the flight (unless you’re seated in the aisle). No one wants you climbing over them so you can keep getting items out. We went over this in Rule 1; have a game plan for what you want handy during your flight, put it in your personal item or unpack it when you get to your seat.

13. Wait your turn to unload

The plane lands, an overhead chime pings, signaling you may unbuckle your seat belt. Unless you have a hair-raising short window between connecting flights, stay seated. Resist the Pavlovian response to jump up that second and lunge for the overhead bin. Instead, wait your turn. When’s your turn, you ask? It’s when the rows in front of you have already exited.