Write the scene setting. As the author of the play, clearly lay out what the setting of the stage looks like to the audience. This includes the place, room or space; the time of day; any important decorations or furniture; and any characters in the scene. Character names should be capitalized, and each character is briefly described when introduced. Additionally, the direction is written in italics. For example, the stage direction for a play set at the town beach might read:
(Williamstown Town Beach. Day. JOEY twists his whistle as he sits on the lifeguard chair. SAMANTHA, wearing her lifeguarding jacket, applies sunscreen as she tries to get JOEY to look in her direction.)
Write the stage direction within the scene. This entails major character movements or actions that are integral to the scene. Again, this is written in italics. Refrain from writing every single movement that you think the actors will make. That direction is up to the director. For example, if you are writing a scene where two characters are becoming romantic, correct writing is:
(JOEY takes SAMANTHA'S hand. He kisses her.)
Or a scene in which they are fighting:
(SAMANTHA grabs her purse, thinks about throwing it at JOEY. Instead, she heads for the door, slamming it as she goes.)
Refrain from writing:
(JOEY takes SAMANTHA'S hand, slides closer to her, brushes her hair back and looks deep into her eyes, before finally kissing her.)
Or the fighting scene:
(SAMANTHA, enriched with rage, grabs her purse, scowls at JOEY, raises her hand back about to throw the purse, when suddenly she thinks better of it. She storms off, slamming the door behind her.)
Both incorrect forms are more along the lines of writing novels or screenplays.
Write the line direction when needed. Although you do not want to direct the actor on how to say every single line, use line direction as guideposts to inform the actor of your intention. The line direction is usually a word or phrase; refrain from complete sentences or too much information. The line direction is written in italics right below the character name, before the dialogue in italics. For example:
CHARLIE
(Can't help but laugh)
or
SUSAN
(completely furious)