Reviews and ratings are always good but it is possible to get sick pretty much anywhere, even in a well rated restaurant in developed country. Some people just have more sensitive digestive systems. While I also used to eat pretty much anywhere and trying most things, my body cannot handle this anymore and I get violently ill from my stomach very easily now.
The best way to reduce chances of getting sick is to go when the throughput is high, so a popular place at a popular time. This happens simply because ingredients have to be replenished more frequently, so they will be fresher when you get them. With street food, there is much less storage space to keep food at a low temperature to prevent bacteria growth, so a place has to restock often, than food will not have to stay out for long.
Exercise caution according to the cleanliness of the area. There are place with much stricter controls and sanitary rules than others. When you see cleaning crews passing often and surfaces clean, food will be more sanitary as well.
The availability of drinkable water in the area is also a strong indicator. Numerous ingredients have to be washed before preparation and so, if the local water is not drinkable, or not drinkable to you, then it will be more likely to contaminate food. One common rule is to avoid fruits and vegetables that cannot be peeled. This rule saved me many times.
Cooking temperature for meat and fish is crucial which is the reason why there are national guidelines in numerous countries. With street food, you can often see the cooking method and learn which is most likely to cook meat sufficiently. Low meat temperature has gotten me seriously sick in many countries, including the US and Canada. Some street food vendors will have cooked early during the day or even in the morning and basically warm it up at the time of serving. This is very bad in my experience. It is better when they start with raw meat and fully cook it right before serving but do pay attention to where they take it from before cooking.
When ordering, consider which items are selling well. If you buy the one off exotic item that rarely sells, you may get sick more easily. This is one lesson I learned the hard way! Consider the risk too. There will be simply times when getting sick is even worse, either because of local healthcare or because of your plans.