Insert these two series of edges with Cut.
Possitions after adjustment.
Look of the nose once subdivided. Work the form with the low poly cage and view smoothing at the same time.
To finish, insert these edges to make the hole of the nose.
Select the polygon as indicated in the picture and made one Extrude inwards as well as Bevel to reduce the size of the internal hole.
Dimentions of the nose in low polygons.
Finished nose, subdivided with interations 2.
Onto the mouth now.
Select the edges edge of the mouth and extrude with shift ket depressed and uniform scale
After having adjusted the vertexes, add edges with Cut.
Stop to adjust the verticies.
More 3D Graphics: 
