Inspired by the animators, I’ve taken to using red & blue 0.5mm propellor pencil leads from Pentel along with Staedtler Marsmicro 0.5mms for light sketches, and red, blue & black Sanford Peel-Offs for heavier work. Mirado Black Warriors are good on smooth paper, but I prefer Derwent Sketching pencils for rougher paper (sketchbooks rather than copier).