So, you decided to plan everything yourself, instead of signing up for a package tour. You are in control, buying the tickets, booking the hotels, and so on. Now, you're there, and you're hungry. What are you going to do?
Finding food and deciding where to eat in a strange locale can be exciting, and mind-boggling at the same time. So here are a few pointers that you might find useful.
Of course, I always advocate doing research. See the recommendations of the guidebooks. I find them most of the time reliable, especially if the guidebook was just released. But, if you don't have one, what are you going to do?
First, avoid tourist trap restaurants. These are usually found near famous sights, where plenty of the tourists flock. Say, the restaurants right at the foot of the Acropolis, for example, or right in front of the entrance to the Vatican City museums. Of course, not all of the restaurants that are near the vicinities of the sights are bad, but there is a tendency to be. Why? Because, most of their customers are tourists, of course, they won't come back again. There is a steady influx of new people since there are tourists coming the next day, and the next.
Another sign for a bad tourist restaurant is if their menu are written in multiple languages, and signs on the entrance saying "Welcome!" in all languages. That usually is a bad sign. Most of the authentic local restaurants are not that way. Most are just the hole-in-the-wall types, and it is the locals who frequent them.
So yes, another sign is the customers themselves. Are the other patrons mostly tourists, or locals? The best lamb chop house in Athens that I had the opportunity to visit was flocked by locals, although tourists also were having fun. It was tucked away in the edge of the city, far from Plaka and the main Syntagma Square, and the food was simply amazing.
Finally, I have to say that looks can be deceiving. The best authentic local food don't always come with a good ambiance. If one is used to high-class dining, one should throw that concept out the window when visiting some other countries, say, in Latin America. In Ecuador at least, the best eateries were in the basements of churches, in small corners in colonial mansions, and other nondescript locations.
In the end, one should have a sense of adventure. Try the local food, taste the local liquor, and enjoy. After all, you didn't book a ticket and fly half-way around the world just to eat Kentucky Fried Chicken or McDonald's, did you?