hmmms... basically what I do to get the 'feel' for new positions is look at photos of people in those positions. That is the best I can suggest. I'm still working on perspective myself so photos and other drawings help a LOT! (smiles)
From the back, that show the muzzle.... hmms... try drawing a circle, which would be the back of the head. The draw a smaller circle anywhere you want the tip of the muzzle to be and then fill it in. Do you know what I mean?
give me a few minutes and I will post an example.