i'm pretty OCD... therefore...
When I leave a hotel room most times I will walk all the way back to the room to check that the door is locked, even if I'm down the hall and have already checked it before I walked away.
I will stop and do a 180 to scan the ground after I take my bill fold out of my pocket to make sure I didn't drop anything, if my brain isn't satisfied with one look I will sometimes turn around again to make sure.
I feel for my phone in my pocket about every 5 minutes or so, even if I KNOW it's still there from the previous 5 minute check.
I'm sure there are more, they just haven't been pointed out to me.