Knowing your neighbors so you can work together if when it is needed, not just food but, securing your neighborhood, medical needs and all that. If you do have a lot of supplies/food, dont skip the lines to get food and all that so you wont become a target. Prepare to make button soup with the neighborhood, "everyone pitching in a single food item into the pot" = everyone getting a little to eat.
I agree that, if it is long term, desperate people will overrun others eventually.