First start with your sense of smell. Walk out onto the street and sniff your way to variety of different restaurants available to you. If they smell bad, try the next one. Keep going until you like the smell and are intrigued enough to try the food.
Next, decide if you want to be able to understand the menu and know what you are eating, or if you want to gamble a bit and test your skills of pointing and guessing. This will eliminate many restaurants because not many will list English on their menu. The restaurants that do have English will almost always tend to be more expensive since they are catering to tourists.
Determine what type of food you want to eat. Check out the menus and pick a style of eating. Depending where you go, you will either be welcome to sit for awhile or be rushed out so the next customer can come. If you choose a food stall you might even eat standing up, if that is your preference.
Check to see if the restaurant or food stall is busy. A filled restaurant means that the locals go there and is most likely safe to eat yourself. I always like to look around and see what everyone is ordering, don’t be ashamed to point at someone’s meal and ask to try that. It is an easy way to discover new foods you like.
Once you are happily in a restaurant (sometimes an hour after this entire process began, depending on your decision making ability), Enjoy! and get ready to do it all over again for dinner! 🙂