Finish sketching out the eyes, and then begin drawing in the eyebrows, and the rest of the horses head shape which is the jaw line. Horses seem to have this large lump like shape for their jaws, and getting the shape drawn right can sometimes be difficult. Once that is done, you can add the lining for the nostril holes, and then sketch out the bangs for the mane. Lastly, draw in the erect ear shape.