Excellent how-to here for eyes, beak, head, body, tail feathers, legs and feet. Examples are from classical paintings.
Of primary importance in painting any animal or bird is regarding it’s main aspect. You will understand this as you ‘connect’ with your subject. Notice the particular “stance” of your subject and it’s bearing.
The Crane is regal and calm and you want to convey that. When you study the examples in this lesson, note the various styles and select one that is closest to your manner of painting. These range from rough and expressive to smooth and elegant.