Firstly I put together a very quick sketch from observation. This was a character I caught walking in my local park with the basic pose being captured very quickly and the detail added from memory as he continued on his way. As I'm drawing, I'm looking for ways to play with proportion, shape and form to create something specific and unique. Favourite tools of choice, Orange Col-Erase on 13x 21cm Moleskine Sketchbook/ Notebook.
Then I scan in the drawing and lay it on some sort of textured paper. This is sometimes left for later (see other example later in the post).
In Sketchbook Pro I start to block in the main shapes using the paintbrush, paying attention to their appeal and structure to the whole. Things are changed at this stage if needed, to help bring clarity to the design. The initial line work is then laid over the top with the pencil, to help define form and detail.
More line work is added, this time concentrating on the face. Making sure I use the initial sketch as reference, I make the forms more solid and make sure the attitude/ expression is readable. I don't want to lose the original feeling I had from the subject, but I do want to push it a little.
Surface texture or pattern is then added. In this case, I remembered the design of his jacket and have included it as a decorative element which is an exaggeration and simplification of the reality. Always thinking about the three dimensional form as I do this.
Then it's a case of cleaning up any areas that are outstanding and adding the context.
So that's a basic overview of the process and hope this gives a bit of insight into how I start to build character from my observational sketching. Below I have included another example to help throw some more light.