For me it's always about first impressions.
I trust my instincts. I love to prepare if it's something that requires training. But I don't like to prepare the psychology too much. I enjoy the psychology of the character but I work better from a first impression.
The mug is a tool. My ace in the hole. To have looks is the bonus on top of what motivates me to be an actor. Not to realize they're an asset would be counterproductive to the cause; they serve the common good.