You can make rocket stoves from large cans with clay in them but they are heavy!
But we found the KGB survivor men! They make rocket stoves just putting bricks together – so we did that. Easy!
We made it slightly fancier by putting a metal plate (an old aluminium food container cut up) for the fire to sit on which means it has air below it and will burn more fiercely. Worked great! We also put it on top of an old water tank to raise it off the ground which makes it easier to use and adds a dry place to store wood. Simple!