At this point do a bit of sculpting of the inside of the cup and make certain the lobe is fleshy enough.

Pull rather than extrude the top outer edge of "layer cake" quads.

The next step is to conform the ear shape to the desired ear.  If you are sketching on top of an image plane then go back to the side view and make the refinements.

Rebuilding the Helix geometry is important to minimize new geometry for edge loops.  I do this by Loop Flow Diverting.  This is acomplished by Quad elimination.  Simply merge two opposite points of a quad.  Be carful where you do this because you can make triangles if you error.

Average the vertices around the perimeter of the lobe and the edges of the Helix facing the cheekbone. At this point a good look at the ear and a bunch of tweeking around the center polygon is helpful.

The lip of the Helix is extruded.  There is a "rising" polygon that can be eliminated by deleting it's edge as it meets the center polygon.

It is wise to point the normals of faces to be extruded in the direction you want the extrusion to travel. 

One can pull the top edge or the bottom edge out to shape the final form of the Helix.  It  depends upon how round you want the outer edge of the Helix. Some people have grown rolled ears.  Some ears are twisty and sharp.  Depending upon the type of ear you can add geometry by looping or extruding and thus preserve surface flow of the quads.

Make the ear canal by extruding the center shape from the back.  This adds a lot of polygons. For low poly counts you can just paint it dark.

The ear is essentially done. Add some edge loops to shape the form. An extrusion in between the Superior and Inferior Crux is needed on some ears.   The walls of the ear can be made very thin and I have been experimenting with ways to make them glow when light hit them.

View other inside out builds at www.2noonS.net