"First impressions. Crucial - first impressions. They're instantaneous, okay? You don't get time to warm up into your character while you're auditioning. So what do you do?
You've got to find the relationships between persons, places, things, and events. I'm talking about your character's relationships. Not what you decide it is, but what it is for the character based on the implications or clues in the text.
How you do that... is find what the playwright implies to you the actor... to find what he or she wrote your character is feeling at that moment. Specifically. Not generally. Specifically.
Example: "Honey, is your mother REALLY coming to spend the weekend?"
What does the playwright imply in that line of dialogue that your character is feeling? It's an implication. A sense.
"Is your mother REALLY coming to spend the weekend?"
Until further information from the writer arrives, in that moment you have to go with what your gut tells you.
You don't get to jump ahead and say I read to the last page and now I know this is this and here's my decision. No. You don't get to know what your character doesn't know yet.
So what does your character feel, huh? Dread? Now, the image I had just then, that I was seeing, was an obese woman in furs dragging sixteen Pekinese behind her as she enters the apartment - calling out "Hiiiiiiiiiii!!!!" That's all I need, that image. That 2 seconds of film. I don't have to invent a giant biography about it. What's in a picture? A lot, when you start having fun. A picture speaks a thousand words, is that the quote? It's true. So, as an actor, that's all you need. But, as an actor, you also have to teach yourself to trust that that's all you need.
I can't teach you to trust. I can give you the tools. You have to practice it. You teach yourself to trust it.
"Honey, is your mother REALLY coming to spend the weekend?"
Ugh, can't you hear her voice? It's right there. You can trust it now because you have given yourself a reason to feel dread. Not in a general way, in a specific way. Okay?"