Sketchbook - face and figure drawings

I am currently reading Andrew Loomis and Burne Hogarth books on anatomy to improve my skills in this area of concept art. They are produced with pencil, and sketchbook pro, adobe illustrator and photoshop.

(done in illustrator/photoshop)

(done with pencil and sketchbook pro)

(red pencil/ pencil)

(pencil)

(biro/ pencil)

(pencil)

(pencil)