Step 1:
The paper is about 20x20 centimeters. Prefold in three parts of the same size.

Step 8:
Fold over this line

Step 6:
Fold over the pink line, use the prefolded line as guidance

Step 13:
Make pleats by folding over the pink lines, do the same on the other side. (The video has more clear instructions about these folds)

Step 12:
Fold in half

Step 11:
Fold over the eight lines

Step 10:
Fold the corners to the spots indicated by the arrows.

Step 9:
Fold over the two outer lines first

Step 5:
Prefold

Step 7:
Fold over this line

Step 3:
Prefold in half

Step 2:
Cut along the prefolded lines and glue/tape all parts together.

Step 4:
This is the other side.
Fold over the two pink lines.

Done!
This is a DIY video tutorial for making the circle skirt: