Here's a recent portrait I did. I say 'portrait' because although pictures of animals aren't usually referred to by this word (they are mostly drawn or painted as representatives of their species: as 'cats' or 'horses'), it is nonetheless equally important to capture an animal's personality in a drawing as it is in that of a human. There is no difference in this respect.
Mitzi was a graceful and patient model and seemed very conscious and pleased with the attention that was focused on her. Of course, there was always the possibility that she would move, which is why I first sketched all the essential things (like the general pose and her eyes) very quickly and why the drawing came out as well as it did. There is a danger, when you have a lot of time, of getting bogged down in details. On the other hand, when you have to work fast you get the essentials down and then improve on them. This makes for a more expressive image.