Giles was also very difficult to do - I didn't want him looking too cartoonish, but he is the most caricatured of the five characters, so his design needed to show this. These were the couple of sketches I came up with.
I liked the last one so decided to colour it up - here are the base colours in Photoshop.
I then did my usual texture experimentation, and came up with the following:
I then pick my favourite of those and came up with this:
Which I then coloured, using the burn tool which is not ideal but has worked well so far, and ended up with this final design, which I am happy with - he is tall and thin, bookish looking to reflect his wisdom and intelligence, with long thin fingers to turn the pages of dusty books, yet his large chest allows for his deep voice and authority.
Spike to follow, my favourite so far ;P