I think someone should write a list of elevator etiquette rules. Because sometimes I don't know what to do. Like if you're on the elevator with an old guy on a Segway. Do you offer to hit the button because he's old and he's on a motorized vehicle? Or do you warn him to watch his head on the way out? I did the former. But he said, "I got it" and zipped up to the buttons and pressed his floor, then zoomed right back to the wall next to me. So I felt really weird standing next to a towering man on a glorified scooter who I'd just implied was impaired. I guess that's a pretty rare scenario, though. But there are plenty of situations that happen all the time where I don't know what to do.
There are some rules that are unwritten, but universally understood. For example, if you're waiting for the elevator and someone you don't know walks up to wait with you, you are required to look at each other and give a half-smile while raising your eyebrows. No need to make small talk or say hello. That's just protocol. It's an unspoken agreement that basically says, "We're about to ride for an undetermined amount of time in a closet-sized space where we are required to look forward the entire time. Let's not make it awkward by interacting before we even get in there." And if you want to see me squirm, turn around and face the wrong way in the elevator. Nothing makes that ride more awkward than trying to avoid eye contact with someone who's facing you from two feet away. It's just unnatural.
But where I really need help is repositioning after someone exits. I was on an elevator the other day with four other people and we were all lined up against the back wall. We stopped once and the three people on the right got off. So that left me and the other guy standing really close on one side of the elevator. I wanted to move over so I didn't have to stand so close to him, but I didn't want to make it seem like I had to get away as fast as possible. I didn't know what to do to convey, "I don't think you smell bad, but I don't want people thinking I'm purposely standing right next to you." So I had to kinda shimmy down a little, leaving enough room so we weren't almost holding hands, but not moving so far as to imply that he had cooties. I think I did the right thing, but I still felt weird.
The only thing I've found to be a concrete rule (for me anyway) is to wait until the doors open before making your exit move. I can't tell you how many times I've made the mistake of taking the preparation step towards the door only to wait 10 more seconds for the doors to open. So I look like I'm trying to sniff the doors while everyone else just stares at me. If I weren't so lazy and overweight, I'd just take the stairs.