keep fixing polygroups for edges, straighten out lines, flatten surfaces, add detail here and there, ridges, rims, extrusions, subtractions, etc
ZModeler, Transpose, Clipping, Move are common brushes/tools used
i tend to use ZModeler alot now, the bike a few pages back was done with only transpose, move and "insert edgeloop" in the geometry tab which was alot more complicated.
But again, if you want clean geometry, work with less, the less you have to worry about, the fewer points you have to keep in line, the cleaner your mesh will become.
Polygrouping and creasing is a good way to keep exactly the detail you want to keep on higher subDs for sculpting the detail