An actor will face two main types of acting auditions: the cold reading and the prepared monologue. Each situation has its own advantages and challenges for an actor, but using a few simple techniques will make virtually any actor look good and win the role.
The cold reading consists of the actor being paired with other auditioners to read scenes (called "sides") from the play that is being produced. The best way to ease any nerves and give a stronger, more confident performance, is to read the entire play before the audition date. That way, the text and style of the play will be familiar, and the appropriate emotion and intensity for each character in relation to the play's storyline will already be known too. During the actual audition, remember to keep the sides below your face so the director will be able to see you and your facial expressions. One of the most effective and subtle ways to keep your place during the reading is to hold your thumb beside your next line, moving it down the page as the scene progresses.
The prepared monologue consists of the actor coming in to the audition to perform a pre-rehearsed piece, usually a speech from a different show. Be mindful of any time restraints the director has requested. Often, an actor will be stopped mid-performance if the time limit has been reached. This is the best way to not win a role. Every actor should have at least two monologues prepared and ready to perform at any time: one comedic and one dramatic. A well rounded actor will also have a classical monologue, such as a piece from Shakespeare or any of the Greek playwrights, in their repertoire. Traditionally at monologue-based auditions, the actor will need to slate. This means the actor will enter the performance space, introduce themselves and the piece about to be performed. Slating is a good opportunity to show your actual personality before launching into the character of the monologue. The monologue itself should be similar in style and tone to the play being produced. Comedic monologues work best for lighthearted, family-oriented plays. Dramatic monologues work best for darker, heavier plays.
The main thing for any actor to remember at an audition is to be respectful of not only the directors, but the other actors as well. A friendly and professional actor is more likely to book a role than a surly, rude actor.