One of the easiest campfires to build and maintain, the "lean-to" fire is a simple pyramid-shaped lean-to built against the side of a large piece of firewood.
Build up the lean-to using pencil-sized wood first followed by progressively larger wood. Leave a gap to insert tinder into the interior.
Cover the gap with small wood once the tinder is alight. Commonly available fire starters include: clothes dryer lint (extremely lightweight), alcohol hand sanitizing gel, a small piece of candle, some insect repellents and even greasy potato chips.