As an actor, your voice is one of your most precious possessions. Before beginning a performance, drink only water that is at room temperature or even warm to keep your vocal cords relaxed. Between scenes, sip hot -- but not scalding -- water with a lemon and honey. When you deliver lines, use your diaphragm to support your voice by using it to control how you breathe and the volume of your voice. These tips will allow you to speak more clearly, louder and without strain, which will make the lines seem more natural.
Comedy acting is sometimes considered to be more difficult than dramatic acting because of the concentration it requires. When delivering comic lines, don't try to be funny. The lines are written to be inherently funny, and trying to squeeze humor out of one line or waiting for laughter makes the lines seem forced and, thus, not funny. Stay focused on the script and the moment so that you don't give the humorous bits away too soon.
Dramatic acting can easily be overdone and be construed as being cheesy. Don't exaggerate the emotions; intensify them. Vivid emotions allow audiences to live through the characters. Because a lot of emotion is wrapped up in dramatic characters, it is important to separate your own emotions and your character's emotions. Your character's emotions take precedence over your own; if you allow your own to peek through, the character will no longer be believable.
Regardless of the type of acting you're doing, you need to be aware of the locations of the other actors on stage, the props and the audience. "Blocking" describes where and how an actor moves while he or she is onstage; directors frame their directions according to the size and layout of the stage. Stay open to the audience physically. Your back should never be to an audience -- this makes it difficult for the audience to hear your lines and to read your body language. Angle your body toward the audience when you're immobile. If you need to turn, always turn in the downstage direction, so your front side is facing the audience.