• keys: very handy for when you need to unlock the door to your apartment. If you add car keys you can also drive somewhere which is very helpful. I use mine pretty much every day
• cellphone: it's like a multitool with a camera, flashlight and a phone. If it's a smartphone you can all use it to access internet. Saved my life many times when I was bored and had to look at some videos online or check the news
• wallet: great for carrying cash, ID and credit cards. It's good to have your ID with you when people ask for your name but you live in a foreign country where no one speaks Polish. You can use cash or credit cards to buy other stuff you need like a bottle opener

Earplugs

For OP and anyone into this thread - If it's not on lemmy already, there was a dedicated subreddit for this called EDC (every day carry).

A towel.

A hardware security key, a knife and some pepper spray is usually what I have, plus my phone but thats a given

Edit: I live in a bad area haha

A tiny keychain tape measure. It's one of those things you have no idea how much you'll use until you have one on you all the time.

Looking at something online? How big exactly is it? It says 16.5" but can you picture that in your head somewhat accurately? It's just easier to pull out your tape measure and see.

I've also started carrying around a small flashlight everywhere I go. I have an Imalent LD70 Mini. It's small enough to fit in my change pocket and it'll put out a blinding ~4000 lumens on turbo (for about a minute before it gets too hot). I do admit that it's not the best flashlight ever. It has a ridiculous magnetic proprietary charger that will short on whatever if you leave it plugged in but it does what I need it to do.

Swiss Army knife, bottle opener, pocket pen, and most important of all: one of those wavy keys to open toilet paper and paper towel dispensers

Depending on how much you want to carry, some of these:

• Screw-lock karabiner, rated for climbing.
• Loud whistle.
• Resqme car escape tool.
• Mini pry bar.
• Mini flashlight.
• Keychain Fisher space pen.
• Mini swiss army penknife.
• Keys ;)

Gerber Shard multitool. Thing has come in handy so many times.

Bonus: Only useful multitool I've found that the TSA won't give you shit over.

Less.

I was the guy with all my keys and fat wallet with all cards and phone + Multitool knife.

Then I got inspired by my sister that travels a lot and tries to optimize for what she REALLY needs.

First I realized that most of my wallet is useless. I started carrying a smaller flip style one with my most used cards and some cash.

Then I reduced my keys to a carabiner with sorted keysets on keyrings, so I carry only the needed ones. Home + bike + cellar for daily use. Home + family keys for vacations. Home for going out. Added a very small key knife and a bottle opener that is part of my daily driver but left when not needed/forbidden.

The current setup is a phonecaee with space for 4 cards and maybe 3-4 bills. And my key setup. Yes you have to remember to take some Special thing. But usually I have my old wallet in my backpack when traveling or when needed.

Sometimes less is more.

A bottle opener, if you can't open bottles with anything like apparently everyone else.

inb4 reply guys: Please don't explain it to me and don't send tutorials I am not asking for help.

Titanium whistle, one saved my life when I was incapacitated and freezing to death.

A bottle opener.

I don’t know about pockets, but my bag usually has(besides the usual stuff) a tiny sketchbook with a pencil. I use it as an alternative to browsing my phone whenever I have time to kill.
Mostly because I feel I spend way too much time on this thing.. like now..

1. Leatherman. I carry a Wave. Got a Gerber and a couple others, but the original (this replaced my 1st gen) is best.
2. Pen & notepad. Always having your own pen that is kept full, and some paper to write someone a physical note, is an amazing superpower.
3. Face masks. COVID is still a thing, don't be dumb. Also carry hand sanitizer or alcohol wipes.
4. Flashlight. I have a small tube 9-LED that's usually in there, but also a 1-LED watch battery thing for the keychain, and I've got a few more around here. Yes your phone has a flash that can be kept on, but it burns battery, and is often awkward. Having light whenever is magic.
5. Switchblade, survival knife, folding knife, etc. Defensive uses, but also heavier utility knife than the Leatherman.
6. Pepper spray, derringer, etc. if you live in a dangerous area.
7. Survival kit. This is more of a backpack item. Get a tiny survival, first aid, etc. kit, there's a million uses for having some cord, bandages, shiny foil blanket, etc.
8. Cigarette lighter or box of matches. Even if you don't smoke, being able to make fire is another magic skill. I keep this with the survival kit.
9. Headphones, I have slightly-better-than-earbuds tucked in my coat. Noisy annoying people just stop being a problem.

And then my phone, keys, wallet, shades. Yes, I buy clothes with a lot of pockets.

A variety of Linux live USBs, you never know when you might want to convert someone

1. I have foldable scissors that are always attached to my keys. They're useful for, well, cutting stuff.
2. Safety pins. Not only that you can use them for clothes (for example if your coat's button decided to detach), you can use them for self-defense if you can't have weapons or pepper spray.
3. A small notebook and a pen. You can write down important things or just doodle out of boredom.

Victorinox knife; FIDO2 key with USB-A, USB-C and NFC; small USB-A to USB-C cable with magnetic cable tie thingy

Edit: I regularly throw in a bootable Linux drive, too

I have a tiny led light that fits on my keychain that I find really useful. It's better than the light on my phone and is a good backup light when I go camping. I also really like the Victorinox Rambler knife. It has a Phillips screwdriver, bottle opener, and scissors.

A security key for your online logins.

If you really want to go deeeeep down this rabbit hole, the words to search are "every day carry". Hide your credit card first though 😬

This handy aspirin holder. Could save the life of someone having a heart attack. https://www.saveaheart.ca/

A hardware authenticator

Chapstick