my medium, the recent rain provided an opportunity to use some good old
fashioned red clay mud. Some slight mixing produced a consistent
thickness to the shovel-full I dug.
For my brush, I broke a limb
off of a shrub that was pretty flexible and a soft-type of green wood.
I then rubbed it on concrete to create a bevel so that I could use the
edge for fine lines and then flip it and use
the full width for thicker lines. I think it worked pretty well.