A year or so ago one of my sons and I made a rocket stove out of a five gallon kerosene can and a some approximately three inch diameter steel pipe. With a cutting torch and a welder, it only took a few minutes to build. For insulation around the pipe, I used dirt at first, but soon changed to lava rock. The dirt worked fine, but I had to move it occasionally and the lava rock is much lighter.
I was able to start a fire and get the stove to work well from the beginning. But like most things, the more I use it the easier it becomes and the more efficient the stove runs. Once you understand the principal of the stove, you can make them out of metal, brick, rock or even clay. They are a great stove to build in a bug out location. They are inexpensive and burn almost anything.
One of the big advantages of this stove is that it will burn the small scrapes that most people leave on the ground. It will even burn things like sage bush. Because the fire is contained, you don’t see a lot of light even at night and as you learn what fuel to burn not much smoke. I would encourage you to build one and learn to use it. It is an inexpensive backup stove. The following is a short video I made of one in my yard.