For this "how to.." I have used the Sitting Gorjuss Girl image from Sugar Nellie.
Firstly I choose about 4 or 5 promarkers from the same colour family, for brown hair I usually use Sandstone, Cinnamon, Cocoa, Burnt Umber and Umber.
I start off with the palest colour, in this case its sandstone, and roughly colour any areas I want highlighted. It helps to imagine where the light source is coming from.
Then I take the next darkest colour (cinnamon) and colour with inward strokes around the pale areas, if the promarker has dried you may need to blend the 2 colours - I do this with the palest colour, taking the strokes from the darker colour towards the paler colour.
I then repeat this for each gradually darker colour, keeping the darkest colour for areas that are in shadow - for instance the hair behind the character's neck and the very tips.
Once the ink has dried on the page, I take either a sakura white gelly roll pen or an inkssential white pen and draw on some highlights on the lightest areas.
So this is what the finished article will look like
this technique works for almost any colour of hair, I have used it for brunette, black (using 5 shades of warm grey promarkers), blue, pink, green, auburn etc
I'll be posting more"how to..." with promarkers soon.