Here's a demo from my Watercolor College Class at Palomar College in North San Diego County. I started out with a Bistre...(explanation below)....underpainting. I used a traditional earth color, Burnt Sienna for the hue because I didn't have the time to boil the soot of wood.....just kidding! Burnt Sienna is a fine substitute for the process. I also suggested Raw Sienna for students who had a great deal of greens in their composition. This will allow the greens to glow.
The glazes were broken up into 3 value steps...light, middle, and dark values.
A Bistre "is a brown pigment made from boiling the soot of wood. Because bistre is transparent and has no body, it is frequently used in conjunction with pen and ink drawings as a wash, a liquid spread evenly to suggest shadows, and is especially associated with the appearance of the typical “old master drawing.”
It was used to its greatest effect in the 17th and 18th centuries, when the bistre wash was especially favoured by such artists as Rembrandt, Claude Lorrain, Alexander Cozens, and Thomas Gainsborough. The pigment is also used by miniaturists." Encyclopedia Britannica
The dark values are added.....almost....this was a demo so I really had to generalize the details....
and a view of the set up....lousy lighting in the classroom by the way......but a good lesson....
and here is the start of the color glazes....as you can see I have more work to do. Tomorrow the class continues and I will return to this painting.....till then.....
Here are some student examples of our great retreat in Texas...wonderful works...thanks dear students!! 
and my color pencil journal page....
