A simple way to create a minimum impact campfire is by using a portable device like a fire pan. Fire pans typically are metal trays or pans such as an oil drain pan or pie pan with rigid sides about 3" high.
2) Use wrist size or smaller dead wood that you can snap with your hands found on the forest floor and not part of any tree.
3) Don't build close to objects to avoid blackening them.
4) Burn wood down to ash.
5) Bury ashes in a cathole or scatter them in a discreet way.
6) Homemade fire pans can be made from an aluminum pie pan and weigh about 0.60 oz.