Usually, we have a big real tree at home, which we decorate with 30-year old glass toys, hand-made ones, dried oranges, sweets and gingerbread animals. Last year it happened that we had to leave just after the New Year, so no one wanted to buy a real tree, plastic ones seemed too obvious and not worth storing for the whole year or even more, so here is my solution.
It's basically a tree painted on the other side of a table board, so it doesn't take any storage space and is not just a green plastic thing that comes from the supermarket.

Step 1: Select Your Canvas

I used a table board that has been lying around since I had grown out of doing homework on a small desk in the living room and my brother is not big enough to need his own desk and not a coffee table he uses for drawing.
It would have been nice if anyone used the table throughout the year, with the tree drawn underneath, but it sadly stays between the fridge and the wall (still not using any precious cm³).
I also thought it can be drawn on the plywood they sometimes cover the lower part of the walls in garages with and kept face back for the year.

Step 2: Draw the Outline

Think of how a Christmas tree should look like.
For me, it was the hardest part - I didn't want and couldn't do it too realistic, wanted something more elaborate than three green triangles and my brother Levi rejected the first red Miro styled version.
Draw it with something - it doesn't matter - coal, paint of any colour, pencil - anything.
Just do it into something you like, it doesn't have to be a masterpiece.

Step 3: Paint

I did it with oil paints, which cover nicely, but require a solvent and take ages to dry.
Probably, acrylic would have been easier, but they become matte after drying, while oils add a shiny finish.

Step 4: Finish, Decorate and Add Presents...

I put tiny nails in the board to hang the ornaments.
However, it was rather hard to find the ones that will fit with the colours, so,
probably, a more standard tree would be easier.
Add presents and enjoy!!!