Another perspective. A trainer once explained to me that we should always, 24/7, be in one of two modes - training or managing. My thoughts are that, if you are training to try to change the behavior, you should seek the triggers, though everyone is correct in that you should be careful not to cross the threshold that sends the dog off the deep edge. For example, passing by a dog at a certain distance under threshold and rewarding the dog for the desired behavior is training. When managing, you are trying to prevent the behavior, so you would want to avoid the triggers. For example, you avoid passing another dog altogether, so that your dog is happy, you are happy, and any other dog and owner you may have otherwise met are happy. Another example of managing is to crate the dog while you are out to prevent unwanted behaviors or to close the curtains/blinds to avoid the dog barking at passersby. Sometimes management is a viable option and is especially useful to prevent self-reinforcing behavior.
Those are just my thoughts, since I'm not really a trainer. I did remember that one lesson about the two modes from a class long long ago.