I sketch using a General's Cedar 2B pencil, on a Bienfang drawing tablet 14" by 20", which is smaller than the finished pice. I do this because I tend to crowd my scenes out to the edges and this gives me a safety margin in the final piece.
The watercolor paper I use is exclusively either Arches or Fabriano. I choose arches for smaller pieces like this as it comes very conveniently in a gummed block (meaning that all four edges of each sheet are glued to all the other sheets, preventing teh paper warping when soaked. The block I created this piece on was Arches 140 Lb rough, 18" by 24" (at over a hundred bucks per block, you don't want to screw up too many third attempts!
I sues a variety of high-end watercolors from the Windor and Newton Artists range, Rowney and Holbein, but I also resort to a child's watercolor set from Binney, because they have som espectacular translucent blue and violet shades that are outside the fine art spectrum. Hard to rationalize why one costs $20 per tube, and the other is $7 for 20 colors (with a free paintbrush).
Most pieces can be completed using only three brushes: a badger hair wash brush (1" or 1 1/2"), a sable round number 12 (Raphael or Ricksson) and a size 0 Raphael. Finally I use a Santa Fe Stoneworks razor ground steaknife to scratch highlights (and things like whiskers) from the finished watercolor.
I drink Bowmore single malt while I work and chew on an illegal Cuban Cohiba cigar. So arrest me.