Eating alone is where a lot of people's confidence fails abroad, and the language barrier makes it worse. You cannot read the menu, you cannot ask what things are, and there is nobody to share the risk of ordering badly.
I have done a great deal of this and it has become the part of travelling I enjoy most. Here is what actually works.
Go where people are eating at the time they eat
The single most reliable indicator anywhere in the world is a full room at the hour local people eat.
Which means finding out what that hour is, and it varies enormously. Eating at seven in a country where dinner starts at ten puts you in an empty room being served by people who are not ready, and it selects for the places that cater to visitors.
Arriving when the room is full is intimidating and it is the point. A room full of people who work nearby, on a weekday, is a place that has to be good because those people will not come back otherwise.
Places with no menu are usually the best ones
Counterintuitive when you cannot ask questions and it holds up consistently.
A place with a short spoken menu, or a board, or a counter with things visible, is generally cooking a small number of things well and changing them daily.
The absence of a written menu removes the reading problem entirely. You point, or you accept what is brought, and the outcome is nearly always better than what you would have chosen from a list.
The version of this I use most is pointing at what somebody else is eating, which is universally understood and universally well received.
Photographs on the menu mean different things
Worth knowing because the standard advice is that photographs are a bad sign.
In many countries they are a bad sign, signalling a place oriented toward people who cannot read the language.
In several countries they are entirely normal and carry no such implication, and avoiding them would rule out most of the good food.
The distinction I use is who else is in the room, not what is on the menu. A place full of local people with photographs on the menu is a place full of local people.
Learn six words, properly
Not a phrasebook. Six things, said correctly enough to be understood.
Hello, thank you, this one, delicious, the bill, and whatever the word for the local staple is.
That vocabulary handles almost every interaction, and pronouncing it approximately right does something disproportionate to how you are received. It signals effort, which people respond to.
Also useful: knowing how to say that you do not eat something, if that applies to you. This is the one worth writing down and showing rather than saying, because getting it wrong matters.
The translation tools and their limits
Camera translation of menus works and is genuinely useful, with two caveats.
Dish names frequently do not translate meaningfully. A regional dish rendered literally produces something confusing or alarming, and the literal translation tells you nothing about what arrives.
And using a phone at the table changes the interaction. Somebody who would have explained something, or recommended something, sees a person occupied with a screen and leaves them alone.
I use it before going in, on a menu in the window, and then put it away.
Eating alone, practically
The social discomfort is worth addressing because it stops people.
In most of the world it is entirely unremarkable, and the self-consciousness is imported rather than observed.
Counter seating is the easiest arrangement. You are not occupying a table, you can see the kitchen, and the person serving you is right there, which produces more contact rather than less.
Lunch is easier than dinner if you find it difficult, because lunch is full of people eating alone everywhere.
And bringing something to read is fine and removes the sense of being on display, though I now do it less because I found I was missing the room.
Markets solve most of it
Where I go first in any new place. Food markets have everything visible, prices displayed, portions small enough to try several things, and no ordering required beyond pointing.
You also learn what is in season and what the staples are, which makes every subsequent menu comprehensible.
And they are cheap enough that a bad choice costs nothing, which removes the pressure that makes people order the safest thing.
The mistake I made for years
Researching restaurants in advance and going to them.
What that produces is a list of places that rank well in English-language sources, which is a specific and narrow selection, generally more expensive and more oriented toward visitors than the alternatives.
Walking around at the right hour and going into a full room has given me better food, at lower prices, in every country I have tried it. It has also occasionally given me something mediocre, which is a reasonable price for the rest of it.