The star fire, or (indian fire) is the ideal fire lay for conserving scarce fuel. Another advantage is that its low flame makes it safer than other fire lays for using inside a shelter.
To form a star fire, make a small fire and arrange logs around the outside facing inwards to form the points of a star. The logs can be of any length, avoiding the need to cut them up. Each log is pushed towards the center as the ends are consumed. You can keep this fire burning with little maintenance; just push one of the longs inwards occasionally.