Take advantage of your school's drama program if your school has one. Get training in stage presence, movement and cold readings.
Enroll in community theater classes and productions. During this training, specialize in theater, television, film, dramatic or comedic acting to hone your unique skills. This will help you become more marketable as an expert in a chosen genre. If you are unsure or have a variety of interests, try to include specific classes in each relevant area to get a feel for which is most conducive to your talents.
Hire a private coach to train your singing voice if you are interested in musical theater. Choose your coach based on other singers' referrals and references in your area.
Apply to a college that has a noted acting program, such as Northwestern, Carnegie Mellon or the Tisch School at NYU. If you can't get into one of these programs, look for a post-secondary school that offers plenty of opportunities for performance along with training in techniques such as those of Sanford Meisner and Constantin Stanislavski.
Have a professional photographer take full-color head shots of you. Be sure to plan the cost of printing as well. Lithograph prints are generally cheaper and sturdier than photo reproductions.
Contact agents in your area about representation for film, TV and stage jobs. You can do this by cold calling or mailing your head shots and resume directly to local offices. Some agents also hold weekly or monthly "open calls," in which aspiring actors can get meetings without appointments. Agents are available in most major markets, including Los Angeles, Chicago, Miami, New York City and Atlanta. If you don't live in one of these areas, you can also reach out to local businesses, TV stations and film schools about acting in commercials, films and broadcast projects in your area to gain experience and exposure.