Tryouts are AUDITIONS. You're onstage from the moment you walk in the door. Dress well, but not over the top. Of course, as everyone knows, appearance is very important on TV, but some shows consider that more important than others. Rub someone the wrong way, and you're out. Catch someone's eye/ear, and you've got your foot in the door. Perform well with charisma and character, and you're almost there. Have a good rapport with everyone involved, do well with your written test/on camera audition, and you may just get picked.
I've auditioned for a lot of things, and also was chosen to appear on Chain Reaction after my first audition. As a matter of fact, they brought us on the show immediately to tape it.
Check out my show TONIGHT (Thursday, Aug 10th at 9pm on GSN) on Chain Reaction!