During exploration, me and my client try to gather all possible significant memories of their past, nightmares, recurring dreams, associated feelings and aspirations.
I have found that my clients tend to pick when they are alone, bored, lost, frustrated, nervous, feeling stuck, are panicked. They tend to pick when they are done with their day's work and are preparing themselves to sleep. Some of them pick their private parts during night in deep sleep, when they are not aware of themselves.