Hi! I’ve done another step-by-step process, this is the first one I’ve done of a drawing. I hope this interests the curious or can maybe provide some tips to anyone wanting to draw a colour portrait. I’ll put in any info I’ve found useful myself, sorry if I’m telling you what you already know.
Firstly, these take a lot of time so you need to like the subject! This is John Krasinski, he plays ‘Jim’ from The Office (U.S version) and I find him absolutely adorable.
Make sure you have a clear photo. If it’s a standard photo size, print it larger so you can get a good look at the detail.
To start you need to sketch out the face. You can do this using the grid method or freehand or transfer paper, whichever way you like. I start in graphite pencil and sometimes shade a bit because it helps me with placement, but then I go over the main lines in a chocolate coloured pencil and then erase all the graphite because it can get muddy when coloured over by a coloured pencil.
Once you’ve drawn out the main features and erased all graphite or grid lines leaving just basic lines in a brown colour, look at the reference and establish the colours in the skin. You’re going to use a lot of layering so you’ll need a few colours that compliment each other and give depth rather than layers of the same colour. I get a yellow like raw sienna, a red brown such as terracotta, a dark and light brown and you always need a dark blue. So, I start with Raw Sienna, hatching all over the face to fill it in. I then get the terracotta and cross hatch over the raw sienna, but now I’m paying more attention to where the darker parts are and giving them more attention. Always keep your pencil sharp.

Next I go over the face again and again with each pencil I’ve selected and using ones I’ve already used when needed, eg more yellow tone, more red tone trying always to keep them cross hatching each other for a more even result. You get a better result if you do more layers rather than pressing hard on just a few layers. As I’ve shaded I’ve used the darker browns on nostrils, lip line, eyelash line etc. I save black until I’m closer to finishing the face shading. Remember to look for reflective light, like the light you see around the bottom of the chin there. I mention it because no art teacher ever taught me that (or that’s a day I skipped school) and it’s so important!
I’ve also started on the eyes here.

Keep going over it with layers, leaving the lighter parts, paying more attention to the dark. Once you think you’ve done enough layers, do some more then get a paper stump out and gently shade over it lightly to blend a bit. Then get your black, sharpen and do your corneas, eyebrows, lashes etc. To shade your eyes to look more rounded, use pinks and purples around the edges of the whites. I shaded lips using a few colours, built up gradually. Use your dark blue/grey type of colour to cross hatch shadows like those under the hair or furthest from the light sourse but mainly to stipple in the slight tinge of facial hair around the chin and where facial hair grows.

At this point I start on hair, stubble, fixing colour that isn’t quite right. Hair is a weaker point for me but what I can advise is to section it out into where the shadows are and where the light hits rather than focusing on individual hairs. Draw the darker parts in the direction of hair growth, then the medium, then leave where the light hits. If you were wanting photorealism, this is the part where you’d probably be a lot more detailed, but I’m not so I move on.

Shading in the clothing and I decided to add background to highlight the hair which is backlit. Now I’m done!
Details: Drawn on cartridge paper 110gsm like any standard sketch pad. Using Derwent and Prismacolour pencils. Time taken: 3 seasons of The Office or approx 3 1/2 days.

Thanks for looking, and thankyou John Krasinski!
Closer detail:

Link to print: http://www.redbubble.com/people/artsez/art/7445250-jim