Start with a square sheet of paper with the white-side facing up.
Fold and unfold along the diagonals in both directions to get an X crease.

Fold and unfold the paper in half (horizontally and vertically) to get a + crease.

Fold the corner of the paper to the middle of the paper (red dot to red dot). Do this for all 4 corners.
This is a common sequence of origami folds:

Turn the model over so the bottom is facing up.

Repeat the blintz fold: fold the corner of the model to the center of the paper (red dot to red dot).

Unfold the model completely so you are back to a square with white-side facing up.

Notice the crease pattern (the pattern of the lines where a fold was made). These creases will allow you to “collapse” the model into pajarita.
Fold the top-right side of the paper down to the bottom left-side of the paper.

Hold down the middle section of the paper (shown with yellow line) while you fold up the bottom section of the paper.

Flip up the bottom right corner. It will “pop” a bit as you reverse the fold.

Fold the bottom layer up and behind the model.

Fold the left section of the model towards the right.

Pull down the bottom-left corner as you keep folding the left flap towards the right.

Fold the bottom layer of paper back and behind the model. The top-left corner of the paper will automatically fold down to form the bird’s head.

Press down flat and rotate slightly.

Done!