How much do you tip the food delivery person?
I never know if I'm doing it right. Do I give too much? Too little? I tend to tip by distance and/or weather. If the restaurant right downstairs from me brings lunch it's one tip, usually a couple bucks, if it's from 10 blocks away and raining it's double.
What do you do? How do you figure your tips? Is it by food cost, weather, distance?