Bear in mind that even when you’re not on your feet, you’re onstage and working.
There is no rest time in an oral argument, for any of the counsel. When you are not speaking, pay close attention to the argument of opposing counsel so that you can respond to any new points or new emphases. Listen to the questions the court asks, and consider how you would answer (you may have to). Be careful, however, not to display reaction to opposing counsel’s argument, as by shaking your head, rolling your eyes, smiling derisively, or otherwise registering disagreement. Maintain a dignified and respectful countenance, and calmly take notes. Similarly, when the court asks opposing counsel a question, don’t display your answer by nodding or shaking your head. Laugh only when the court laughs (and, for that matter, weep when it weeps).