Step 1:
Both sides of this paper are completely pink.
Prefold over these 4 lines.

Step 2:
Make a valley-fold over these 4 lines.

Step 3:
Make a valley-fold over these 4 lines.

Step 4:
Prefold over these 4 lines.

Step 5:
Pull the corner indicated by the arrow to the left by making a mountain-fold over the (prefolded) line on the right and a valley-fold over the line next to this line. Make the same folds as above over the 2 lines on the left in this picture.

Step 6:
Repeat step 5 on the places indicated by the 3 arrows.

Step 7:
Now the model looks like this. Turn the model.

Step 8:
Hold the model the same as I do here. Pull the ends indicated by the 4 arrows inwards, almost in the same direction of these arrows.

Step 9:
Now the model looks like this.

Step 10:
This is the bottom of the flower.
Make a valley-fold over this line.

Step 11:
And make a valley-fold over this line (above my thumb).

Step 12:
Press the model flat from the inside and outside between your fingers on the places indicated by the arrows. Now the model looks more rounded at the bottom again.

Step 13:
The flower is ready...

Step 14:
You can use this leaf to fit with the flower.

Click here to see diagrams for making this leaf

Finally the flower is glued to a stem.

Click here to see diagrams for making a stem

Done!

This is a DIY video for folding the paper Tulips: