Although this is a technical skill, an actress must be able to memorize her lines. They sometimes shoot several pages of scripts at a time, and may receive changes to a script within minutes of taping. Memorization skills should be honed and improved.
An actress must be able to share her emotional life with her character. Many scripts require actresses to cry on cue. While there are some cheats available, there is no way out of expressing a truthful sadness.
An actress must be able to hit exact marks---without looking down---while reciting dialog and emoting. Marks are places where an actress must stand, often in take after take, so the camera can get the appropriate shot.
An actress must be able to take rejection. She land one in thirty or so auditions, but only if she is lucky and talented.
From headshots to resumes to business cards, an actress has to be able to sell herself as if she were an irresistible business entity.
According to the Screen Actors Guild, the average actress does not make her living by acting. Honing her skills and pursuing a dual career can save an actress from falling into the dead end jobs.
Singing and dancing skills are invaluable, especially in the New York City world of theater. An actress who can sing, dance and act is sometimes called a triple threat.