Practice Dramatic Scenes

I had the same experience and was quite worried about my sim not being able to prepare properly for her role, until I found out that lack of preparation made little (if any) difference to her performance on the day. Once at the studio, her success (ie, whether or not she got gold) was determined by doing all the specified actions -- including all the inconsequential "gossip", "tell story", etc, interactions, which logically shouldn't have made any difference to her success in the role. As long as she did everything specified and didn't flub too many scenes with her risky acting, she invariably did well.