What do you do when ..

[sally]

I don't find elevator silence to be awkward.

Typically, I just smile then face the door, watch the numbers, and exit without any thought of socializing.

If someone starts talking or needs assistance, I always engage though.

Same here. If I'm closest to the buttons I'll ask them which floor or if someone gestures to let me out first I'll say thank you, but other than that I don't say anything unless they talk to me first. Just your regular elevator etiquette stuff.