A simple paper box version. This is my first instruction here and I tried to make it as clear and understandable as possible. It was difficult for me to explain some of the steps so that it was clear, but I think that everything will be clear from the photographs. If you have any problems, write in the comments and I will try to explain better.

I know that there are several versions of A4 paper boxes, but here I have not seen my way, so I hope it will be useful to you. Enjoy!
Stage 1: Materials

You will need:
- 2 sheets of plain office paper (box + lid)
- Scissors
- Pencil
- Ruler
You may also need some glue.
Stage 2

Fold a sheet of paper as shown in the photo.
Stage 3

Draw a line with a pencil, tracing one of the sides of the resulting triangle.
Stage 4

We cut a sheet of paper along the line.
Stage 5

Now you have a square (you can throw out the extra piece of paper).
Stage 6


Now you have to fold the square on the other diagonal and unfold it again.
Stage 7


Then fold all 4 corners of the square towards the center.
Stage 8


Fold one side of the square towards the center (as shown in the photo), then fold the opposite side in the same way.
Stage 9



Now bend the sides of the square that have just been bent. We rotate it 90 degrees and bend the other two sides of the square in the same way.
Stage 10


Make cuts as shown in the photo. The cuts should only be at the top and bottom, they should not be too deep or too short.
Stage 11


Expand the top and bottom as shown in the photo. Fold the other two sides so that you get a box.
Stage 12


The final stage of assembling the box. We bend the remaining two sides. Done!
Stage 13


Now, if you have a desire, you can make the bottom for our box, i.e. the box we made in the previous steps will become a lid (it will be difficult to insert one box into another if their size is the same). In order for the lid to fit easily onto the box, we need a ruler.
It's pretty straightforward. First follow steps 1 through 5, and then measure and draw a line 5 mm from the top and right edges of the square with a pencil. Then cut off these thin strips. The bottom and lid will now blend in perfectly.
It remains to repeat steps 6 to 12 and the box with a paper lid is ready!
Stage 14


If the inner triangles bend down at the top, then they can be fixed with glue.
Stage 15



All that's left to do is connect the boxes together.
I have added some examples of how you can decorate it or make it funnier. The box can be made in any color or size, from different types of paper … now only your imagination limits you: P