A bit of very rough sketching just recording ideas.

Started with a simple base mesh and tweaked his face to get the first glimpses of his personality.

Laying down some basic skin textures using polypaint.

I wanted him to have some kind of eccentric waistcoat and as I don't have any full formed ideas in other directions I decided to start with modelling that. The texture for the waistcoat was made by making an interesting design using Alchemy, a great graphics software for creating chaotic designs. I set Pull shapes to all Shapes and just started laying them down in a haphazard manner until it looked cool. Then I took it to afinity photo and added colours, duplicated and overlayed a few times and just kept playing with it until I liked the design. I actually love the final texture so much as a piece of standalone art I'm considering having it professionally printed and framed and hung on the wall 

Here you can see the waistcoat being rendered as velvet in blender cycles.

Then I decided to add some formal black trousers.

I'm thinking a shirt under the waistcoat with this kind of cravat

The blazer design there is awesome too so I might do something like that either as a blazer or a trench coat.
I really like this goatee and possibly a similar hairstyle

I'm also thinking he should have a silver-topped cane which doubles as some kind of magical staff. Something like this:

Next I'll model the shirt and settle the question of what will be over the top, blazer, coat, something else, or nothing.