Again, the most common mistake is forgetting to ask the question. Maybe it happens only when others are present. Every problem occurs in a context of the things around it at the time that it happens. Figure out all that is happening at that time. They are laid out in steps that you do one after another.
Problems occur the same way.
First this happens, then that happens, then the next thing happens. The pitfall is that we often think of a problem as the final step in the process. In reality the problem may be at one of the steps along the path to the problem. Make sure you describe the steps of a problem to get a good picture of it. When it comes right down to it, a problem is a problem because someone thinks it's a problem.