My personal rule is – if I didn't tip for something 5 years ago I don't tip for it today. Restaurants, taxis and food delivery make the cut, as do most personal services like cleaning and haircuts. Self checkouts, grab and go items, food trucks, fast food, online shopping, convenience stores, grocery stores and lots more all get $0 extra from me with absolutely no guilt. Oh and the default 20/25/30% options all come way down as well. If others want to get socially shamed into it, well that's fine by me.