Every time you go into a restaurant, grab handfuls of napkins, ketchup, sugar, etc.
not just restaurants...gas stations and supermarkets that have lunch-bars where they offer utensils, salt/pepper, assorted high-end condiments (specialty mustards, tartar sauce, oil/vinegar, peanut butter, etc)
also...hotels for the truly desperate. wander around until unattended carts are found where there is a treasure trove of towels, laundry detergent, cups, linens, toilet paper, cleaning supplies, and in the high end hotels, coffee, assorted hygiene items, better linens / towels, popcorn, etc.