The key is to have your Sim click on the microphone and Watch the awards show. They'll sit where they want to, and probably play musical chairs the entire time, which is disrespectful to the host, but a lot more fun to watch than if the entire audience was still and silent the entire time!
Be sure to watch the notifications during the show, too. If you see the notification that your Sim has won, click on the microphone immediately and select "Accept Speech." If they don't accept the award, they won't get the trophy.