There is interesting architecture on B Street in San Rafael, around the corner from Rileystreet Art Supplies, where my Thursday drop-in sketching workshop meets. Here are the stages in my sketch of part of a building.
The first “pass” is done with a dark red aquarelle pencil, to put the basics down as quickly as possible. Then I used a Micron .08 pen to add some line work. Next I added turquoise pencil strokes and used water to blend color. The final version includes some dark accents made with a Faber-Castell B (brush) pen.