When people walk out to meet you on "leave at door" orders...
My biggest pet peeve by far. I always assume they are going to report undelivered. It has become so common I have received the "30% of orders missing photo" warning twice... so I stopped hitting "handed to customer" and insist I take a picture.
To any customers who do this thinking you are being kind or helpful, it's really not. If you don't want your food on the ground, please request "hand to me" not "leave at door".
Edit: I am not complaining about people meeting me at their door. I am complaining about people not following their own instructions and walking AWAY from their door to come to me before I get there, specifically when there is no reason to do so (not lost, late or bad weather) and when the instructions say "leave at door".