Watercolor has a reputation of being a difficult medium. Because the pigment is absorbed into the paper, you only get one chance. There's not much you can do to fix mistakes.
I use 300 lb. Arches cold press watercolor paper. This is a wonderful archival paper that is very thick, has a rich texture, and consistent sizing.
I use several different brands of watercolor paint. The most important thing is that they are lightfast; manufacturers list the pigment rating on each tube. I keep 20 colors but only use about 12 of them on a regular basis.
Because I'm interested in capturing a quality of light and a subject matter that is perishable, I set up each still life and take photgraphs of it. I use the photographs as reference material and work from the actual object as well. This allows me to spend two to eight weeks on each painting without worrying about the cherries drying up or the quality of sunshine each day.
I begin each piece with a detailed pencil drawing; putting the drawing down on paper helps me map it out in my mind. As I draw, I think about how I'm going to paint. In fact, it seems there's more of the drawing in my head than on the paper: if I've completed a drawing but am not able to begin painting right away, I find I have a lot of difficulty. It's like I've lost my place in a book and can't remember what's gone on before. I make a conscious effort to plan my work so that I never go out of town with an unfinished piece on the drawing board.
After the drawing is complete, I dampen the back of the paper, then flip it and apply a light wash of color to everything but the areas I want to leave white. By wetting both the front and back of the paper, I avoid some buckling of the paper. Because I use such a heavy weight paper, I don't need to stretch the paper by taping it down or stapling it. This allows me to paint all the way to the natural deckle edge.
In photographs, the background in my paintings may appear to be naked paper. However, I always apply a subtle wash of color to them. The only bare paper you'll find is in the brightest highlights.
I use just a few brushes- a one inch flat sable and a number 6 or 8 round, and occasionally a fine number 4. I'm rather hard on the 6s and 8s and go through quite a lot of them. I'm still using a one inch flat brush that's over 20 years old.
I work by applying many successive washes of color. Some paintings have as many as 30 or 40 glazes. These never build up above the surface as a glaze in oil painting would, but because watercolor is transparent, the many glazes work together to create a complex result.
When the painting is complete, I dampen the back of it again, cover with acid free cardboard, and stack books on it for 48 hours. This flattens the paper and removes any buckling that happens during painting.
The pieces are framed with archival materials with white or off white mats. I generally like to 'float' the painting. This means that the linen tape hinge is completely behind the painting and the mat is cut so that you can see the natural deckle edge of the paper.