Here's an interesting quote of how he prepared for an acting role:

Asked about his acting methods in 1973, Mr. Borgnine told The New York Times: "No Stanislavsky. I don't chart out the life histories of the people I play. If I did, I'd be in trouble. I work with my heart and my head, and naturally emotions follow."

Sometimes he prayed, he said, or just reflected on character-appropriate thoughts. "If none of that works," he added, "I think to myself of the money I'm making."

Charley Noble