There is no technique more important or effective as listening.
There are layers of listening to employ, having to do with structure, content, tense, etc.
The more you understand the structure of a story, the better able you are to identify anomalies.
The most obvious example if listening for past tense or present tense in the appropriate manner. When a traumatic memory surfaces, quite often the client will slip into present tense, without noticing. It can be very helpful to address this and make the client aware of it.