Perspectives in Narratives

In a creative writing class once, the teacher was explaining that writing a story needed a personal element but also needed to be distanced from personal bias. He would say wait a long time, don’t write in first person, present tense or other things that would be helpful in distancing yourself from the story.

When he was talking about this it occurred to me that whenever I write something with strong personal themes, I usually find myself telling the story from a first person perspective of a male narrator. It makes it easier to tell the story and helps to eliminate the personal bias.

What techniques do you use to help keep the story impersonal?