Photoplayer Hater

Actors can learn a lot from people that have nothing to do with acting. Most people can't be the same to everyone they meet though they might not be conscious of the difference. You aren't the same person with your friends as you are with family, but you don't look at it as acting. Even your friends act differently around you than they do with other friends. We calibrate our behavior depending our desires and feedback we get and we know we're doing it right when nobody calls attention to it.

Parents

Any American has been lied to by a large proportion of parents for a good period of their growing up. If it's not how toy guns can shoot your eyes out or your face will freeze with a certain expression on it, then it's the fact that there is a Santa Claus. Not only did they have to believably deliver bogus improvised dialogue to convince you that this man existed, they also created stories that go along with the performance to make the whole thing seem real.

Salespeople

You go into a store hoping to buy the cheapest TV they have. You have to deal with a salesperson to actually purchase the thing and suddenly this person you just met feels like your best friend. He's mirrored your posture and inflection. He seems able to anticipate your every concern and expresses that sympathy sincerely. Then he is able to slowly help you change your mind and upgrade to a DVD player and surround sound system. He sure does have your best interests at heart and he seems so much like you that it's hard not to say yes. If you have any doubt whether it's true love, just say "no". You'll immediately see him become the hardened professional dollar-snatcher he truly is. You won't even do that, though. That's how good they are.

Prostitutes

She asks me if I want some company. She knew that I was lonely and took the initiative unlike so many women I know. When I get her to the hotel room she is so attentive and looks at me so lovingly. I think she's into me. She lets me keep the light on and doesn't care that I'm a 60-second man. This must be love, nobody can fake this. To see if it's love, don't pay her. You'll see how much you mean to her. But you won't withhold payment, because you don't do things like that to people that love you.

Teachers

They are the model of decorum and etiquette. Always with a kind word and sound advice. Share with your classmate, don't be greedy. She seems an angel sent here to tell us the right way to live. When she gets home she doesn't share, share, share and isn't the supportive saint she plays at school. This never crossed your mind because you never doubted the authenticity of her demeanor. You couldn't imagine her ever being like that, until you get a peek at the real teacher when the whole class isn't able to master fractions. Then she throws books and raises her voice and you see how much she's been acting the whole time. But she would never do that because she truly cares for you.

The fact that nobody has called these people on their "acting" proves they are doing it well. Don't just look to proper "actors" for tips on how to be, look around for "normal" people and they may teach you something no actor had thought of. People do things to get things. Watch them and you can pick up great ideas you wouldn't have thought of. Every single person can teach you something, don't overlook their wisdom.