From the age of about five to twelve I was very bad, a hideous little terror who beat people up. I was a member of the Rough Gang - we went around and terrorized all the pupils in school.
Pick a theme and work it to exhaustion... the subject must be something you truly love or truly hate.
In 1969, at the age of 19, I was lucky enough to work with George C. Scott in the definitive portrayal of his career over a period of many months and several countries on the definitive film version of Patton's WWII career.