Here's a tip.
Before I turn around to see you a foot away from me while I'm waiting in a line as you need to grab your pop out of the cooler right behind me is when you say excuse me. Before.
You don't say excuse me as I've already turned to see you in front my face. and after you startled me
Excuse me works like this.
You say it.
Person hears it.
Then moves.
Then your turn.
This has to do with manners, not social distance.
You know, grown adults use words.