This is the first step after the 'preliminary base'.

Next, fold the WHOLE top triangle down.

The 'petal fold' in progress.

A clearer shot of the petal fold.

The petal fold complete, laid down flat.

Now, flip the whole thing over...

...and do the same petal fold steps on the other side.

Here are both side pieces folded in to the middle.

Again, fold the top triangle down...

...open the flower, and then...

...finish the petal fold. This is called the 'bird base'.

Fold in the top layer of each side, to meet the middle.

Then flip the whole thing over and fold in the other sides the same way.

This shows the pre-fold needed before doing the 'reverse fold' that forms the neck and tail.

This shows how you open up the sides. Then turn the point 'inside out' to make the reverse fold.

Here's another shot showing the reverse folded neck. Do the tail the same way.

Neck and tail folded and creased flat.

Fold down one wing...

...then flip it over and fold down the other.

Missed a few steps, but here is the final product.

Flap flap! Enjoy your crane. Make 999 more!