Split poly, merge vertex, delete edge, delete vertex, extrude, component move, scale and rotate mainly.
However its sometimesfaster to work with just creating one face at a time (poly append), against a sketch or two. Also sometimes its great to have a nurbs reference behind (for detail). And some parts done with birail.
Also keep in mind that you want to avoid using anything other than 4 sided polys (stacked neatly with othe four sided polys)
Also once your model is finished use the original poly object as a low res proxy thisway you can work much faster. And then subd or swich to subd just before rendering!