The way I draw my portraits

 

I took a normal A4 sheet. I drew a head of eyes, nose, lips and outlines for face and hair.

I took the three poster colored jars.

I mixed light brown and yellow and made a watery mixture. For lighter tones.

I mixed light brown and red and made a watery mixture. For darker tones.

I painted the face with the above. I had now three distinct zones in face. Blank, lighter tones and darker tones.

I allowed the painted face to dry under fan. About 10 minutes. 

Then I used lighter reddish brown, darker reddish brown, lighter brown and darker brown Mont Marte skin colored pencils.  I shaded suitably. 

Then using black Mont Marte skin colored pencil I shaded hair.

Then using red Mont Marte skin colored pencil I painted lips.

That's all.  Thanks.