Instructions
Make a list of the autographs you want.
Categorize them into columns by profession and location.
Get on a computer with internet access, and look up their name in online search engines. Some have both official websites and site pages on popular networking sites. You'll want to look on their official website for an address where they can receive fan mail. Movie databases and their union might also be a place to look.
Write down the addresses of your favorite, and write them a letter.
Make sure to tell them about yourself and how you're a big fan. Thank them, and explain certain things you particularly love that they've done. Let them know how much an autograph would mean to you.
Include a self addressed and stamped envelope. This will increase your chances of getting a letter back.
Decorate your envelope. Make it stand out. This could be as simple as drawing on the back or choosing a colored envelope.
Be prepared to wait. Some celebrities write back right away, but others may take months and months. They are busy, and some handle fan mail all on their own. Be patient.