I like to go buy some popsicles or ice cream treats and give them to outside laborers on summer days. They are amazed and grateful. It is an easy and inexpensive thing to do. Also keep a few extra umbrellas in the car to pass out to people walking in rainy conditions, and stock up on cheap gloves that I have been known to give to anyone coming door-to-door without them in the winter.
Your post reminds me of a number of places I have been where there are “community umbrellas”. People just leave them for other folks going out and those going out take the umbrellas. Good idea on keeping a few extra in the car.