Materials Used
I only use high quality materials - even for daily sketches and project planning sketches. Yes, they it is more expensive to maintain stock of paper and paints but in the end they simply last longer. Brushes last longer and are more predictable. Paper is more archival and take the graphite or painter better. Paints are often more vibrant, require less layers and again, more archival. Most importantly, the work lasts much longer.
Brushes
I only use brushes made by Rosemary and Company and I generally use the pure kolinsky sable brushes but I do also have synthetics from Rosemary.
Paper
The watercolor paper I buy is usually Fabriano Artistico hot press in blocks. It is 300gm weight and acid free. For smaller works and sketches I use Stillman & Birn watercolor sketchbooks. My toned paper work is done on Canford Card Stock in a few different shades of grey. My preference for toned paper sketches is a line of Strathmore toned sketchbooks and I have a few different sizes scattered around the studio and in my backpack.
Graphite and Charcoal
I've come to trust the Staedtler Mars Lumograph line of graphite pencils for their very soft leads that go up to 8B. This allows me to get good darks with very little burnishing (sheen) on the paper. I don't always use them though. My favorite tools for drawing are .5 mechanical pencils. I have several Pentel Kerry mechanical pencils that I purchased when I was in high school back in the mid 80's. I have added a few more Kerry's over the last decade so I can have different lead variances at my disposal. All that said about the Kerry line, recently I have been trying out the Pentel GraphGear line and I really like the weight and balance of these mechanicals. An added benefit to this pencil, which I recently just noticed, is it has a hardness indicator on the pencil that can be changed with a twist of the barrel.
I buy charcoal from General Pencil Company in both pencil and powder product.