When you are taking on a role as an actress or actor you want to be able to fully develop your character. The trick of good acting is making good choices.
Read the play. Once you have been cast in a role you want to read the play for it's content. Restrain from reading the play to see how important your character is. Read the play to understand what it is about and why the author decided to put pen to paper. You may need to read the play a few times but you want to understand how each character relates to one another and how they all tie in to the main events in the play.
Step2
Relate to your character. You were chosen for this role because there is something about you that the casting director saw that related to the character. How are the two of you alike? Would you make the same choices in the given situation? Can you relate to any of the other characters that your character has to relate to in the same way? Can you relate to your characters surroundings? How is this character you?
Step3
Get rid of indicators and stereotypical choices. Make this character an actual person: you. If you are tired you do not always walk around yawning. If you are upset it is more interesting to see what you do to make yourself not cry rather then to cry on cue. If you are mad it is more interesting to be quiet then to yell and scream. Take a few days to try and experience life through the mindset of this character.
Step4
Be truthful. This may be easier said then done but the more honest you can be the better you will be able to relate to the character and the better the audience will be able to relate to you. People come to see a show to watch people relate to life. You are up there as an actor to pour yourself out on stage so the audience can have a cathartic moment or come to a realization or just be entertained.
Enthusiast 
