I add a few more details and definition using the ClayBuildup brush. At this point we probably need more resolution to work on more details, so I increase the Resolution. The Polish switch defines the planes of the face after DynaMeshing, but you can also use the Blur slider to smooth all major details on the model: high values produce a smoother surface, while a value of 0 will respect the smaller details.
Before and after applying the DynaMesh process with both Smooth and Polish enabled.
You can click and drag the Blur slider to change the value, or simply click it once, to apply a precise amount of blur.