Looking closely at what I've just done and comparing with some books, I can see better now the reasons behind the choices of materials used for various instances. I started this journey trying out red pencils on toned paper, and have moved to adding red washes for compositional studies. Looking again at the masters and thinking about the limits to this technique, I think I'm getting close to having a handle on things.
In my latest experiments below (other post) I am trying for a more full tonal range with the watercolor wash. The problem I'm having is that once I reach a dark value range with the washes, they obscure the drawing below, and I lose the linework which has to then be re-established. Another thing I just realized is the color choice is wrong for compositional work. The reds work well for figurative work, giving life to the flesh, but the reds are too foreign a color to use broadly in a scene composition. Related to this, I have tried some black pencil over the red to strengthen some darks, but there is another discordance here in that the red and black become busy and the surface jumps out and is not unified.
After considering these issues and looking at some good books, the technique I need to try next is brown ink and brown wash. This is by far the most common drawing combination in my books, and after considering my recent experiments it makes perfect sense: The brown ink/wash combo is a subtly warm medium that gives the drawing color vibrancy without being too strong to look out of place for shadows. Black would be too dead and harsh, and red would have too much color to be used across a scene where the tones essentially describe shadow and should be played down. The brown allows for a line to sit back in space in the background of a scene, and doesn't jump forward like a black line would, allowing for the values to be controlled and built up. The ink pen allows for a tapered line weight, and is strong enough to be seen through the wash. Additionally, the brown wash alludes to the first stage of a painting where the tones are established in umbers, which unify the darks. Some examples of brown technique below...
brown ink and grey wash: moving towards describing warm/cool in addition to value...
The combination just described should work well for general light/dark compositional planning, but this is not to say that other combinations aren't better for specific uses. For instance consider drawings where cool/warm is indicated in a scene by the use of red and black washes and drawing media; the faces being red and fabric or backgrounds treated in greys and browns.
Here is an example where greys are used to simulate background cools and shadows that contrast against warmer light areas.
warms in the flesh, cools elsewhere:
Brown ink with warm and cool washes:
In addition, the red pencil by itself is still great for more detailed figure studies, where the linework needs to be clear and there is alot of detail and subtlety to describe. I guess what I've learned is that you need not just one tool or technique, but a few- and the flexibility to chose what is appropriate for the scene.
Well, back to the drawing board, as it were...