Step 1:
Prefold over these four lines.

Step 6:
Press the layers between the purple arrows against each other and fold the center of the model to the right, see short purple line.

Step 5:
Fold these four edges in half.

Step 2:
First, fold over the two lines below, then over the two lines in the middle. And then over the two upper lines. All folding lines are prefolded.

Step 4:
Repeat step 3 on the other three edges.

Step 3:
Fold the edge in half.

Step 10:
Press flat from aside, see purple arrows.

Step 8:
Fold these two edges downwards over the purple lines.

Step 9:
And fold the other two edges downwards.

Step 7:
Fold the center further to the right.

Step 15:
Curve both flaps / ribbons

Step 12:
Bend / curve the upper two flaps.

Step 11:
Fold the center around the flap, use glue if necessary.

Step 14:
Fold the two lower flaps in half.

Step 13:
Glue the tips to the model, see arrows.