The fundamental elements can trip even the most sustainable camper up. A reusable water bottle is a camping no-brainer. Invest in a good one with a hook on the cap to clip onto your backpack, and make sure it's insulated to keep water ice cold or tea piping hot.
To refill, bring a large, reusable water container with a tap for the campsite - these are available from camping stores. If you have to do a supermarket water run and get a plastic one, buy at least a few litres in bulk, never individual, smaller plastic bottles.
For ice, avoid plastic bagged ice from the servo and instead freeze water in used milk bottles or ice cream containers (remember to recycle after use) and throw them in the esky. Make ice out of salted water and it will stay colder for longer.
To get the campfire going, ditch the plastic disposable lighter for a metal flint fire starter. They’re cheap (from $10) and you can use them over and over again. Plus, you’ll feel like you’re on Survivor making fire with your bare hands.
Ranger tip: Check if there are any planned park fire bans before you go. If there’s a park fire ban in place you will not be able to light a campfire or solid fuel barbecue or stove.