Step 1:
This long paper is made of four squares glued together, the other side is white. Prefold over the orange lines

Step 6:
Open the model, see arrow

Step 5:
Fold the blue part in half, do the same on the other side.

Step 2:
Prefold. Fold the line on the right in the middle of the edge and the prefolded line, see arrow.

Step 4:
Make the same folds on the other side.

Step 3:
Squash-fold the part on the right against the part on the left.

Step 10:
Make the model flat, see arrows

Step 8:
Use the prefolded lines as guidance

Step 9:
Squash-fold the part on the left against the square on the right

Step 7:
Prefold over the diagonal line first, then over the line on the left and then over the line in the middle.

Step 16:
Fold the tip backwards, repeat on the other three tips.

Step 15:
The two diagonal lines lay behind the upper white part.
Make the same folds on the other three corners.

Step 12:
The line on the right goes behind the upper part

Step 11:
Fold the center part in half

Step 14:
Fold the four corners outwards

Step 13:
Fold over these four lines.

Step 18:
Prefold over these four lines.

Step 17:
Make scharper folding lines.

Step 19:
Fold the four corners inwards and the edges upwards. Use glue, if necessary