Always look at a piece, especially birds and animals, as what part of the object is closest to YOU the viewer. Not top or bottom, Picture the real life object in your mind, if you reach out to it, what would be the first thing you touch? That's what is closest to you. So, if I look at the face of a dog, looking at me, the nose is closer that the eyes, or ears, so I would start there..and work away. In the case of your bird, the wing is closer that the head, or body, and when you are seeing feathers that overlap....the top feathers would be closer that the lower ones, so I would shape the top feathers, then the middles and then the bottom ones.
Hope this clears things up for you