DMIL had mobility issues and we made sure she and her wheel chair were on the same deck as her muster station before the warning sound blasts started.
DCL makes several announcements over the P.A. telling people of the upcoming drill, and how soon it will start. Just be off the elevator before the warning blasts.
After the drill, a lot of people head for the closest elevators. Depending on where your muster station is, you might want to find something else to do for a few minutes instead of fighting the crowd(!) at the elevator.
In the event of an actual emergency the crew would have carried DMIL down the stairs to her station. That's something she (and they) didn't want to practice.