In order to fold it I first crease an octagon exactly in the center of the paper square. For the box I crease an octagon which width and height are equal to 1/3 of the width and height of the paper square. I can easily do that without leaving marks inside the octagon. The problem is with the lid, in order to fold it I need to crease an octagon in the center of the square which width and height are equal to 3/5 of the width and height of the paper.
Here is an image of the octagon of 3/5 inside the square:

Can you please help me find the best sequence of folds to do this? It would be perfect if, during the process, the octagon doesn't end up with creases inside.


