Step 1:
This is the front of the paper, the backside is completely blue. Make mountain- and valley-folds over these 4 lines. Unfold each fold after you've made one.

Step 6:
Press the edges that stand upwards flat from above, see arrows. Use the lines you've prefolded in step 3 as help-lines when you do this.

Step 5:
Pull the end at the bottom of the arrow upwards by making a valley-fold over the yellow line.

Step 2:
First, make a valley-fold over the 2 lines below, on the right. Then, make a mountain-fold over the 2 lines in the middle. And make a valley-fold over the 2 lines on top, on the left. Now you get a basic-shape.

Step 4:
Unfold the folds you've made in step 3.

Step 3:
Make a valley-fold over these 2 lines. Make these folds over the upper 2 layers of the model.

Step 10:
Repeat step 9 on the other 3 petals, see arrows.

Step 8:
Fold the piece at the arrow on the left downwards by making a valley-fold over the yellow line. Do the same with the piece on the backside of the model, see arrow on the right. Then turn the model, so all petals are on top in the picture

Step 9:
Make these valley-folds on the edges of the petal. The end of the petal (indicated by the arrow) is pulled downwards a little when you make these folds.

Step 7:
Repeat step 3 to 6 on the backside of the model.

Step 11:
Curl each petal backwards with your hand or around a pencil.