It’s not proffesional, its just the way I do it but maybe it will help you somehow ;)
This is what we are going to draw:
In the begining I draw basic sketch, its easier to start when you see whole shape of face. Just in case dont draw lines to hard so you could erase them later if something went wrong.
I always start with eyes. First I coloured black areas in the middle of the eyes and than iris, which should be darker up. I draw some eyelishes, remember that they can’t be all in one direction and that the eyelishes at the lower eyelid should be thinner and lighter.
Here’s a my another tutorial how to draw eyes if you had problems: http://www.facebook.com/photo.php?fbid=245121722224450&set=pu.129199420483348&type=1&theater
And eybrows, you draw them just by doing short lines.
I finnished eyebrows and I put some shadows around the eye. While doing shadows first make it light. If you have different kind of pencils its good to use 2B or HB for that. (I think everybody have HB pencil coz its the normal one)
I also marked places on nose when later will be the darkes places, and I started doing lips. I draw teeth better and uper lip.
I put more shadows on the left side of drawing. Heres a tip: if u are right handed start with drawing left side first if you are left handed start with right, thats how you dont smudged pencil.
Its better to do light shadows first and than make them darker when its needed. I also draw some hair and lips. I draw lips just by drawing lines, some should be darker and some not, remember to left some white lines too.
I finnished upper lip and I added more shadows. The middle of nose and areas under eyes shouldnt be shade to much.
it doesnt look realistic so you shouldnt separate teeth with lines, but you can do light shadows on sides so they will look like they have shape.
You do down lip same as upper on, with lines. The middle of lip should be left almost white.
I finnished lips and I shade all face. I started doing neck, first I shade it all softly and than I put darker shades when it was needed.
I finnished hair and neck and put more shades on face. Justins jacket is easy to draw on this pic coz its just black with white elements, so I dont think you will have problems with that:)
At the end I draw background, I made it dark but you can draw it however you want, its up to you:)
Hope I helped you at least a little and don’t don’t give up on drawing if something is going wrong. Just practice:)