Decide to whom you should send your portfolio. Go to Backstage.com and find the Call Sheet. This is a list of all casting directors, agents, and managers in the United States. Choose from this list people who could help your career the most. If you're a musical theater performer, write to casting directors who specialize in this area. If you're more of a television actor, write to casting directors who specialize in television. For general representation, write to agencies and managers who seem to share your views of the industry, and ask to meet with them in person.
Find a photographer to take your head shots. Pick your favorites ones and print them on 8-by-10-inch photo paper. Type your resume to include your professional experience, education and special skills, then cut this paper to fit on the back of your head shots. Include photos from past productions on another sheet of photo paper, if you wish. Finally, add your cover letter. Keep it personal and brief. Explain why you're sending your portfolio to this manager, agent, or casting director, say thank you, and sign your name.
Type out each address onto a small, printable label. Do not address portfolios by hand as this looks unprofessional. Create or purchase your own return address labels. Many programs allow you to add designs, or even your own photo, to your return address labels. You want the person to be curious when she receives your portfolio, since she receives so many. Makes yours stand out so she won't throw it away before opening it.
Fill your envelopes with your head shot, resume and cover letter. To ensure the envelope stays in good condition, you may even want to stick a thin piece of cardboard in the envelope so your head shot doesn't bend. Weigh the envelopes on a postal scale or take them to the post office to make sure they have the correct amount of postage. Place your envelopes into a mailbox and cross your fingers that one of them pays off.