Acting the first six lessons by Richard Boleslavsky
Dramatic Action. For each beat have a verb you are trying to achieve through the words to be said. And choose the verb for your character: a high court lady could "be insulted" but it is stronger for her to "preserve her dignity" it fits her station better and it's easier to do then to be.
An actor brings to life a unique human soul for every part. "This human soul must be visible in all its aspects, physical, mental, and emotional." Not just a young woman who could be Sally or Ella or the actress' twin, but specifically Ophelia's soul.
Characterization of the body: Use what you know: who was Ophelia? the daughter of a courtier. which means: she is well bred and well controlled. So look at paintings of courtiers by Raphael and Da Vinci. Borrow the hand poses from Boticelli's Birth of Venus, and the head posture from the Mona Lisa, "the clouds driven by the wind can inspire your walk"
"Characterization of the mind in the part on the stage is largely a question of rhythm. The rhythm of thought I should say" Shakespeare did all the thinking for Ophelia, so you need to try and understand and adapt to think the way the author does. To apply that to a part "it is mostly the rhythm or organized energy of your delivery of the author's words. After studying him and rehearsing him for a length of time, you ought to know the movement of the author's thoughts. They must affect you. You must like them. Their rhythm must infect yours. Try to understand the author."
Characterization of the emotion: "emotion is God's breath in a part. Through emotion, the author's characters stand alive and vital." Basically you need to have your part all worked out through actor's craft (know what dramatic action you are trying to achieve for each beat, have your lines memorized so they flow easily, be able to give yourself phantom sensory input to react against, incorporate things you've seen real people do, usual acting craft stuff)
An exercise to develop observation " I decided that for three months, from twelve to one every day, wherever I happened to be and whatever I might be doing, I would observe everything and everybody around me. And from one to two, during my lunch time I would recall the observations of the previous day."