my aproach would be to think about edgelooping first. basically I model the whole "thing" at once, means I dont model the head, then the torso, etc... I create a cube and cut/extrude/whatever. as a matter of fact I use extrude a lot. the extrude operation gives you a mesh which is distributed in a clean way in terms of edgelooping. I then flip faces to alter the loops and extrude again to create a denser mesh.
but you cant get completely away with haveing a highResolution mesh in one area and a very lowResolution mesh in the area beside it. try to distribute the mesh evenly. when you create blendshapes afterwards and try to animate it you will understand what I am talking about now.
have a look at maya´s masterclass DVDs from jeff unay he is called I think. he explanes some really cool hyperrealistic modeling techniques. the best tutorial on modeling in my opinion is from Freedom of Teach - Human Modeling. it doesnt matter if you like human modeling but it shows exactly how to get around the troubles you have.
gl!
everything starts and ends in the right place at the right time.