Whether painting with bristle or soft-hair brushes:

Thin color with lots of solvent & sketch main shapes with a small, round brush.

Color/block in the biggest, most important shapes with big, flat brushes; thin paint to a milky consistency with a touch of medium and solvent.

Still work with big, flat brushes, refine & adjust colors & shapes; no details yet.

Work with medium-sized and small brushes to place final touches and details. Don''t overdo it!

Resist the temptation to use small brushes; the right brush is the one that seems too big for the job!

Hold brush in middle of the handle, not like a pencil too close to the bristles.