The Dancing Brush makes a flat brush use its precise stroke abilitiess to build an image without mud as the paper stays flat.
Colored Pencils
Surprised? Colored pencils are a fine art medium. They are economical, portable, very forgiving, engaging etc, etc, etc. They allow tremendous detail in a small area, but can and will work large format. They work on dry surfaces, especially colored papers, in any color. Their ability to depict brilliant detail helps when a watercolour may need a touch of ???.