Here's my top tip for getting your hair cut in another country: just accept whatever they give you.
The fact is, over the past several decades British people have been getting haircuts that are on the whole slightly different than those that the majority of Americans have been getting. So, if you go in and be very specific in asking them to cut your hair just like they used to atGreat Clips, your instructions will be diligently ignored and you will end up with something that is almost but not entirely unlike the thing you asked for. So, your best bet is to instead focus on finding a place where you like the people who are cutting your hair in whatever fashion they please.
When I lived in Portsmouth, I always went to a barbershop that was located in the train station. The two guys running the place had thick Mancunian ("from Manchester," FTYPAH*) accents, so I generally never understood a word of what they were saying. But they were friendly enough and they seemed to think I was a comedy genius for once having made fun of Thunder and they only charged £5.
In Cardiff, my place of choice is Pontcanna Barbers on Cathedral Road. Every time I go there, I feel good for the rest of the day.
It's your basic old-school single-room barber shop, with four black and shiny silver barber chairs on one side of the room and a row of wooden seats for waiting customers on the other side. Scattered on the seats are always the day's tabloids, all opened to the sports section. It would simply be some sort of weird throwback but for the all-female staff. Dressed in all black, they give the whole thing that sort of hip feel that Gen-Xers are so desperate to achieve in everything they do. Except that here it feels authentic.
I don't know if anyone in Wales uses the phrase Gen-Xers, and of those who know what it means, I'd wager that very few of them give a toss (FTYPAH: "very few care"). A good thing about Britain is that once you move beyond university level age differences and the application of generational titles tend to fade away.
The barbers use straight-edge razors, rather than clippers, to trim edges, which strikes me as particularly hardcore. And they use talcum powder! They use a little horsehair brush to put talcum powder on your neck when they're done cutting your hair. I don't think I've been to a barbershop that does that since I was 5 years old and got dragged to my grandfather's barber shop. I keep waiting for them to give me a piece of Dubble Bubble gum.
What really sells it, though, is the fact that they act totally surprised when you give them a tip and they always say goodbye. I'm a simple and sappy man, I know, but having them all chime "bye, love, take care," as I'm leaving is the ego equivalent of suddenly stepping into brilliant sunshine**.
*Bryan suggested I shorten the phrase "for those of you playing along at home" to an acronym. I think this one works best because it can be pronounced: "fitty-pah."
**In an effort to sound all intellectual and stuff, I was going to reference Robert Frost's "Dust of Snow." I had always interpreted it to be a poem about how tiny things that can shake you out of extreme misery, but I am shit with poetry, so I could be way off.