Start with a low cage so you have very little verts to move around, the subd modifier will smooth it out without artifacts. Once you have the base, collapse it with enough geo and then start detailing. Sometimes i simply build my topology with retopo tools on top of the collapsed base mesh (subdivided 2 or 3 times as needed). I start with the "seams" and then fill in the blanks, when comes time to split parts at the seams, chamfer "open" with a low value (can always go back to this step for biger gaps), throw on the shell modifier and turbosmooth. With the shell modifier you can use splines to bevel your edges sharper or smoother. Other times you can get away with the double smooth method and modifiers. Yeah that's a pile of gibberish but i hope you understood some of it! XD