Merge the marked edge.
Extrude the marked edges.
Extrude marked edges again forming the bottom of the mouth.
I've extruded a single edge marked above.
Extrude where marked.
I'm getting bored of typing it but extrude again.
And again. And time for a mesh update I think Base Part 11.
Extruding 3 edges here to form the upper part of the top lip.
Extrude the marked edge and deleted a point from a triangle.
Marked in green extrude edges, marked in red merged edge's to form the corner of the mouth, if you don't want the triangles you can just delete that edge, but I'll just leave it for now.
Extrude the edges to form the lips.
Extrude the same edge to form the inside of the lips.
Now on to the nose, extrude marked edges.
