madart is basically right, you should study references a lot, and simply ‘test-sculpt’ your way to improvement. Comparing the finished smoothed surface to the reference. Nothing else matters. IMO you can get away with some triangles, and even more 5-sides, at least in Maya, but madart is suggesting some good changes for you there.
The rule of thumb is - for slightly curved surfaces (like most of the human body):
A triangle that is skinny WILL create a narrow bump or crease.
A triangle that is small, surrounded by larger quads, WILL create a more circular bump.
A quad that is small, surrounded by larger quads, WILL create a bump (circular or stretched, depending on its shape).
A 5-side surrounded by slightly smaller quads can become almost completely smooth, especially if you use the Average Vertice command. (So it’s a good way to end extra edge-loops.)
Now, if you want a bump, if you pick the right kind of polygon to make it, you can really keep the poly-count low. If you don’t want a bump in a particular place, now you know what to avoid.
But your biggest problems are the forms - the clavicles should reach from the sternum to the acromion (bony apex of the shoulder) for instance, much more horisontal than this. And the nostrils are a little strange, try to move in closer, with a good photo reference of a nostril, or a mirror, and focus on that exclusively for a while. The ear also may need some more work.
Overall though, you have a very good start there - cranium, neck, shoulders, basic shape is solid.
Allenatl and Alouette: both very good! 
Alouette, about hair, well that’s my nemesis, so far at least. I’ve tried geometry hair, Shave&Haircut, Maya Hair, PaintFX, Fur, Wildcat Toon render, and all of them leave something to be desired. I guess for me, geometry hair gives me the most control, even with it’s limitations in terms of realism and animation.