I actually threw this together to respond to a comment, but figured it might actually be worth uploading.
 
Usually before I make a picture I whip up a very simple sketch to get a rough idea of how it’s going to look when it’s completed. For more complicated and indepth pictures I’ll redraw a much higher-quality (though still somewhat rough) version (see here for an example), but for very simple poses like this I can easily work from the simple sketch alone.
 
For this picture specifically I was practicing various ear positions and then rolled with it to make the ear flapping thing.
 
The finished picture: