The swan bases on the bird and is quite difficult to fold because of its complexity. There are many more steps needed for finishing this figure.
Please fold accurately!
Step #1:
After you have put the bird figure in front of you on the table, fold the upper folded layer up in a valley fold and close it again.
Step #2:
Fold the uppest site on the left to the right and redo step #1 (fold the new upper folded layer up in a valley fold and close it again).
Step #3:
Turn the folded paper around and redo step #1 (fold the new upper folded layer up in a valley fold and close it again).
Step #4:
Redo step #2.
Step #5:
Please erect the folded paper in front of you and take the inner two cusps between your thumb and forefinger of the particular hand. Disperse both cusps as long as you note a light resistance of the paper. But never mind. Keep dispersing carefully till the center of the mountain fold between those two cusps turns up and you've got a big "mountain" as center line.
Step #6:
Put the paper back on the table and and take the left part of the "mountain" as well as the left edge of the paper between the fingers of your left hand and do the same with the right side and your right hand.
Push your fingers slightly together and push your hands together till they are next to the center. Turn the mountain fold to the back for creating two new foldings between the corners on the bottom of the back and the center of the edges of the triangle. Please note, that the cleavage between the two edges of the triangle builds one line with the vertical center folding of the "mountain".
Push both sides - at the left and the right side of the other triangle at the front - onto the other paper layers on the table, push your hands together again and fold the triangle in the front exactly onto the triangle at the back.
Step #7:
The wings of the swan will be finished in this step by folding both upper cusps of the triangles to the back.
Do a diagonal valley fold from the right corner at the bottom of the triangle to somewhere on the left egde of the triangle. Try to fold the upper cusp in that way, that the cleavage will be on the same height as the upper edges on the left.
Turn the paper around and redo this step but to the right, so that the one wing is on top of the other.
Step #8:
While you are folding apart the folded paper stick the one wing below the other wing. It doesn't matter which wing sitcks below the other because this step will be undone afterwards.
When you have stickt the wings together, turn the paper around and note that the wings are showing to the right. We will fold ne neck and the tail in the next steps.
Step #9:
For the neck are only two easy foldings needed.
Fold both sides on the left to the center folding as far as each side is exactly up to the center valley folding.
Step #10:
This step is for the swan's tail.
Fold the triangle on the right to the left and do another folding back to the right. The distance between those two creases is not defined but you will get a nice result if the distance is about one fifth of the whole triangle length.
Step #11:
Shut the body of the swan long ways and do either the two first steps of an outside reverse fold or only a valley fold for the neck. But please consider that the neck is folded parallel to the back of the wings and don't forget retightening this crease because you have folded 8 layers paper at once.
Step #12:
Open the neckfolding and also the body of the swan a little and put it onto the table.
Step #13:
Finish the outside reverse fold for creating the neck and do another outside reverse fold for the swan's head. There is no size defined but try to adapt the head to the whole body of the swan.
That's it :-)