First, I cover the jar with paper clay (I used "Das modelling material" but you can any paper clay or even a homemade paper clay). I don't use natural air dry clay, it will shrink and that will result in a lot of cracks around your jar.
DIY Fairy House Lamp Using Jar
Hello ! In this tutorial I show you how I made a medium sized fairy log house using a coffee jar, aluminium foil, hot glue, paper clay and acrylic paint. It’s fun to make and you can use it as a decoration, secret hiding spot, or you can even turn it into a lamp by adding some battery operated LED candle lights
Secondly, I cut the carton to two circular shapes (or three depending on the desired thickness) and I glue them using hot glue. Afterwards, I cover it with clay.
And still using paper clay, I added mushrooms and other plants. Also, I add an ax and trunk of a broken tree. With the same way, you can easily add more details using paper clay.
I used aluminum foil and glue with the lid of jar to build the basic shape of the roof. I covered them with paper clay while adding a roof window. After, I covered everything by posing above already prepared autumn leaves.
I used acrylic paint for painting. You can also use watercolors and watercolor crayons. It's up to you. In the end you can seal the paint using some matte spray varnish. I placed some battery LED lights under the house. I recommend you use soft lights that will gently illuminate your windows so it looks like a real house.
You can see all the details in Tutorial Video in my Youtube Channel. "Creative D2H"