You can either describe what you want, or show a picture of a haircut that you like.

I tend to bring a picture or two of the style I want.

"I dunno. I suck at this. what do you think?"

don't do that at the cheap joints.... but otherwise it usually sets up a good discussion.

protip, if you're wanting a men's style... go to a barber. usually less expensive, and usually much better at men's style. (Also, most barbers don't care if your a man or woman or non binary. they still won't charge you extra the same way a stylist will charge some one passing as a woman women's rates for the same thing. it's pretty absurd.)

I throw up some confusing explanation with gestures before my barber does the same haircut they did to me for 5+ something years. Idk what would I do if they retire.

I usually just show a picture because I never know what the styles are called, I just know I want it on my head.

"Like it is now...only shorter."

Describe it however you want. If you have a decent barber, they should understand you fine and work with you.
I've been shy, straight forward, and all manners of sides when asking for a haircut and the biggest issue has only been the occasional language barrier.

Once you're comfortable in a style it'll be easier to use different wording, depending on how you want your style. For example: you most certainly can ask for clipper sizes, like "no. 2 on sides", however if you don't know what you want from the top you could just ask them "a bit short but matching the sides, if you know what I mean?"

Some styles have different options, such as skin fades (usually medium or high here, indicating the point where the fade reaches on the side and back of the head). If you're unsure definitely do not be afraid of asking, if any barber has an issue with working with you they aren't the barbers you want as they're likely to rush the haircut regardless of what you say (in my experience), or only know limited styles/lack broader experience in hairdressing.

I bring a picture of myself with the haircut I want.

Husband says tight fade, zero to very short on top and that gets him what he wants, he goes to the same barber lady all the time, she doesn't speak English and he doesn't speak Spanish but they still manage to communicate the haircut information.

"One haircut, please."

I show my hairdresser a picture of my previous haircut (or one I like).

If they're good at their job, you can ask pretty much anything and they'll ask follow-up questions. If not they'll infer what to do or do one of the standard haircuts.

"the usual", because i don't know what hairstyle fit me and don't know what its called. I tend to ask what hairstyle fit me and then get the same haircut everytime.

"I'm not really sure, what do you suggest?"

i show them a picture of my cock. please make my head look like this.

I say: make my hair beautiful/better (in the local language). I don't really need to do anything else, it seems to work.

I tell them:

"3 on top, 2 on bottom tapered. Yes I know it is short."

Haven't failed me yet. As long as you know what you want, they usually do a good job. Try to get the same barber each time and you might not even need to say depending on how often you get your hair cut.

I like low maintenance, and generally have my hair cut once a year right before summer when it gets hot.

You need to be more specific. The last thing barbers need is having to guess what you want.

I get a 4 on the sides, a low taper to 0 on the back, and then say how much I want off top in inches. Letting them know how I comb/style my hair seems helpful as well.

You can also just google a hairstyle and show them a picture.

You think that's hard?

Last year my dentist/denturist asked my what I wanted my teeth to look like!

It was unreal, trying to develop an aesthetic preference for teeth. It was actually quite eye-opening. I did find that I had a very strong opinion about it. I haven't quite gotten to the end product, but I now know what I want.

I recommend photos, but also to be careful in explaining what you like about the photo. It's easy to latch on to one aspect of a style, not realizing that an attempt to reproduce other aspects might end up completely ignoring what drew you to it in the first place.

No guard till middle of the ear, #1 with a high and tight fade, finger length on top with a little longer in the front, textured, white walled and squared off.

I'd say something like "Hey I need a haircut, just something shorter (or whatever you thinks best)."

I take a selfie when I get the haircut I like and show them the picture next time. Nice and easy.

1-2 on the sides, blend to longer on top, usually comb it over messy like this, just needs to be shortened up on top.

Make me look like Mr Clean.

Consequently I have not been to a hair salon in 30 years, a razor in the shower is all I need. Although one day I would like to have the whole hot towel shaved head treatment at a professional barber.

Explain what you want. It’s that easy.

I did many years of “I want something simple that I can maintain easily, and will still look ok when I drag my ass out of bed at 10am, an hour late for work. Anything but a buzz cut”

Eventually I found something that I can touch up at home myself, and can explain to even the shittiest of barbers.

It’s hair. Nobody really gives a shit. You’ll get some shit ones, some good ones, a buzz cut you explicitly didn’t want. Nobody got hurt, and it grows back.

Mines pretty simple. Clippers (#2) on the back and sides, scissors up top.

Yeah you just describe what you want and they will tend to do it. I just get away with walk-ins at JCPenney salons, but if you get particular about your style you can find a stylist or barber that can learn how you like your hair.

My hair was about 3ft long at the beginning of last year. I'd normally go for a haircut every two to four months and ask for them to take two inches off and add layering.

Last summer it was getting too hot gardening with how thick my hair gets, so I asked for the back of my head to get shaved as an undercut about at my glasses line. Hair looked the same when worn down, but I could put it up to cool things down. I had to go in every month or two though to keep it short enough to keep me cool, so every other haircut I asked for two inches off and layering.

I let the undercut grow out from October to June, and had maybe 6 inches of hair? With no layering it looked a bit flat when I wore my hair down.

This summer I decided to get a Mohawk for better ventilation. Asked for the sides to be buzzed leaving about a 4 inch wide strip running from scalp to back of neck, for 6 inches off the longest part of the hair that was not originally part of the undercut, and layering to be added to both the longest portion and what was the undercut.

I typically wear my hair to the side, so it looks like I just have a little undercut and can pull my hair back when gardening to cool off. It would probably look silly if I put up my hair with gel, but after 6inches of hair it really is a pain to put that up. Also I have a kid, so there is no time for extensive styling.

Over winter I'll probably aim for every two to four months for haircuts since I don't need the sides so short. Goal is probably 6 inches off the longest part until it levels out, and then just decide how long I want it in that style.

I'm pretty easy, I just ask for it to be cut shorter and go with whatever they suggest.

"Hello fellow human. I require a haircut. Something like this please shows picture. Thank you"

Depends on how picky you are. For me, I don't really care so I say "3 on the sides, trim / a little shorter-or- longer on top".

#2 on the sides, tapered up to finger length up top. Leave me some extra in the front

"A #6 on the sides please, fade it to about an inch shorter than it currently is on top."

I just ask them to please do anything they can to fix whatever my hair is doing, inasmuch as possible, and to remove as much volume as they can without it getting out of control (too long, and it's a chaotic uncontrollable mess; too short and it's also a chaotic uncontrollable mess; these two states sometimes overlap... but I don't want to shave the whole damn thing).

It usually works for a week or two until it starts getting long enough to start getting completely out of control again.