A standard piece of advice to anyone traveling to a new country is to pick up a few key words or phrases in the local language. Mine was usually "I am a vegetarian." Over many years of traveling, I learned to say this in various languages: "Soy vegetariana" in Madrid and Mexico City; "thathalo" in Myanmar; "Ich bin Vegetarierin" in Germany, and so on.
This phrase did not get me far in some countries. In France, for instance, saying "Je suis vegetarienne" invariably brought forth contemptuous looks and boiled vegetables. And in Asian destinations like Thailand and Cambodia, I had to keep sniffing suspiciously at my food, because fish sauce is not just a condiment but soul food in those parts. Also, I once had to pick out pieces of pork from my noodles, thrown in by a kind chef taking pity on my "tasteless" dish.