For sketches I use my Brushy brush and a slightly altered version of ×ェ×’s character pens. My alterations to their pen were pretty minor - I reduced the variation in brush size, especially at the start and end of the stroke, to make it more like a standard lineart brush.
I use my Grain brushes and another altered brush to refine the lines. Instead of creating a new layer for my line art, I draw the line art on the same layer as my sketch. I use these brushes to draw and erase, adding and subtracting from my sketch to clean it up.
I don’t use Rough or Bumpy too often, but they’re good for cleaning up line art and creating fine detail. I use them to create intricate details and patterns that are actually just a bunch of little scribbles and loops when you zoom in
