I wanted to practice digital rendering using Sketch Book Pro combined with the Wacom Cintiq so I picked a Ferrari to copy. The image is made up of approximately 80 separate layers. Starting with the outline and then adding any black areas and blocks of colour, finishing with the highlights. The main bushes I used were the air bush and the marker, I used the erasure tool to neaten all the edges (which is why there are so many layers).
I appreciate its not perfect, but I think it has an element of realness to it and its about 20 times better than my first ever hand render using marker pens (I'll try and dig that out at some point for comparison)
At university I studied product design, a lot of people said it was a colouring in degree, I would say I learnt how colour really well and to keep within the lines!