I didn't really use a ref. I've been drawing GSDs for years so I don't need to ref them. The pose is just the normal show stack that they use for show GSDs. It is used to show off the dogs side profile. Most dogs are drawn in the side pose as frontal poses are quite hard to do. The difference with my German Shepherd and all the others is the fact that it's back end does not slope downward. Most GSDs you see do. But the best don't. If you look at old black and white photos of the first GSDs you see how straight backed they were. Most police and guard dogs are straighted backed as well. But show GSDs and most American GSDs have badly sloped backs. Thus the reason why GSDs are more prone to hip problems than any other breed. My grandma Mona use to breed GSDs imported from Germany that had straight backs. She tended to breed more of the unloved solid whites though. They had bad temperaments though and were prone to bitting. She now only keeps one for protection a classic tan and black saddled.

My favorite dogs too!  I think if you added some "noise" pixels to the coat it would look more fur-like!  Also the pink in the ears could use some blending with the rest of the ears as it really jumps out (almost glowing!).  Over all good job!