Defining the detail on the nose

Using the cut tool while vertices are selected enables you to divide a polygon into more edges. This enables you to add more detail where it is needed. It was used to add more definition around the nostril.

By selecting the edges around the nostril and holding shift and dragging up the Z axis a copy of the edges were made. This created the nostril cavity. The scale tool was used in the same way.

The cut tool was used to make sure there were only four sided polygons making up the nostril, as when the turbo smooth was applied the odd shapes create pinches on the model.

Nose cavity once turbo smooth has been applied.