Origami passo a passo

Bem dobrado!
First, you need a pentagon. Try this: http://origami.oschene.com/wp-content/uploads/2006/11/pentagon-from-a-circle-scp.pdf
Then, you need a pentagram, connecting the midpoints of the sides of the pentagon.
Now, the little pentagon in the middle of the pentagram is the bottom of your box.
Fold the edges of the big pentagon to the little pentagon. This makes a mid-sized pentagon.
The space between the little and middle pentagons are the sides of the box. You make folds at right angles to the sides of the big pentagon to the corners of the little pentagon. That's how wide your box sides are.
You can collapse the box at this point and it will go together, but it will be flat, dull, boring.
So, we add curves. Fold the edge of the circle to meet the intersections of the pentagram points and the corners of the box sides. Try it, you'll see. Then, pinch in the curves.
The last bit is the mountain fold from the corner of the box side through the point of the pentagram.
Now, collapse it as you did before. Good?
Make one out of bookcloth: http://www.flickr.com/photos/oschene/sets/72157602418672831/

Teia de aranha psicodélica - adorei.

Yours,
Philip