I have been meaning to take progression photos while doing a painting to document the process but once I start painting I usually don't take the time or just plain forget. I finally remembered so the following is my typical process for executing a painting. This was a scene from the Portland Japanese Garden that I painted for a friend.
This is a quick sketch used to establish the light, mid and dark tones on the painting. With watercolors its very important to know the areas that will stay light because once you paint over them there is no way to lighten them.
Not all the details are drawn but enough to give you a good guide, it is very important to get the perspective right at this stage and not be guessing once the paint is flowing.
light yellow wash - these area will be the highlights where the sun hits the grass
drop in some green and let it mix with the yellow on the paper
start to work in the shadows
Add the pink values for the flowering bushes
Build up dark values and details. I like splashing on paint with a toothbrush to give the bushes texture and it just fun to do.
Finished up with the tree trunks and some hints of branches, stones between the steps and some shadows on the ground.
I sometimes like to leave the bottom or corner of a painting unfinished so the viewer can get a sense of the many layers of washes that give the painting depth and a good sense of light and shadow.