Sometimes small accessories can be detrimental to the ability to implement something. For instance, Could you ski without the proper equipment? Or cook without pots and pans? No way!
Zero waste is the same way. There is no way you can be a successful zero waster if you haven't packed the right utensils.
I give you the must haves in a prioritized list. Pack wisely.
Reusable CupThe human body requires a minimum of eight glasses of water everyday; hydration is critical. Therefore my number one zero waste essential is a reusable cup. Not only can it be used for coffee, water or a smoothie, but you could also jam some leftovers in there if necessary.
Tiffin Box Or Food ContainerThe no brainer, I usually pack lunch up in these things in the morning, and when I come back home later in the day, it's filled with compost scraps (apple cores, banana peels). This is also great if you grab something on-the-go. At a restaurant, I usually order my food dine-in at the bar, then wrap it up myself.
SilverwareI could count on one hand the amount of times, I have visited a common kitchen that has real silverware. Always stay strapped, it's the perfect protection against trash.
Cloth napkinProbably the most underestimated item on this list. Of course a cloth napkin is a for wiping your mouth and drying your hands, but in a moment of extreme circumstance
—like an unexpected trip to the grocery store— then BAM! your napkin is now a pouch for bulk dry goods.