1. Hire a professional photographer to take photographs of you. If a professional photographer is too expensive, consider a photography school student. Many talented students will photograph you either at a reduced rate or for free. Most agents merely want a sense of how you photograph, and can easily determine if you photograph well even if you don't have a fancy portfolio. Instruct the photographer to take both head shots and full body shots in different settings with several different outfits.
2. Begin a modeling portfolio by purchasing a bound portfolio with plastic sleeve pages. Insert several of the best photos from the photo shoot into the portfolio. Do not worry if you only have a few photos. As you gain experience as a model, you will add to your portfolio.
3. Go to a printing company to print a stack of model composition cards. Known as comp cards, the cards are printed on 8 1/2 in. by 5 1/2 in. card stock and include photos and vital statistics such as height, weight, age and hair color. Also include your name and contact information. Typically a comp card has a head shot on the front and several smaller images on the reverse.
4. Contact talent agencies in your area that represent children and preteens. Many agencies hold open call days when prospective models meet with scouts and display their comp cards and portfolios. Although you can also send your images to an agency by mail, it is usually more effective to meet with agents face-to-face. Agencies post open call times on their websites.
5. Sign a contract with an interested, reputable agency. Read over the contract carefully with your parents or guardian and ask questions about anything you do not understand. On receipt of your contract, the agency will sign you up for auditions and contact you about upcoming modeling calls.