'Play the Part' - or getting inside your character's heads, might have been another way of putting the focus of July's 'Beginners' page in Writing Magazine. It's a useful trick if you can pull it off, if only because it allows you to step aside from your own persona while writing about a character, and absorb yourself in how he or she might talk, think or behave. Do it well and it will project itself onto the page and avoid all your characters sounding similar.
It's also much more enjoyable for a writer to inhabit these parts - especially the villains - because it allows us to get down and get dirtier than we might otherwise be. I've found from experience that it makes the writing easier, too, because once inside their head, the dialogue, mannerisms and actions pretty much write themselves.
The idea for the article came to me after seeing a mediaeval re-enactment group staging battle scenes over a weekend, during which time they dressed, ate, drank and lived their parts, including scripted running battle scenes in the nearby forest with much clashing of battler-axes, swords and other weaponry. (There was also a fair bit of abuse in the air, but since much of our modern-day foul language seems to originate from the middle ages, you can't say they weren't staying in character).
Mind you, one member (a large and intimidating man with an awesome battle-axe, did fall out of character at one point when he pulled out a phone and was heard to say, 'OK, mum - I'll be leaving shortly. See you later.')