One of his strengths is that his drawings are dynamic, even when they don’t contain any background, as in the case of the Komodo dragon.
As for brushes, I can’t help much: what I use most in Krita for the outlines of drawings is a G-Pen, slightly modified by me.
In my opinion, the best way is to perfect your lines, the way you want, without relying too much on stabilizers. There’s an exercise I did recently, as described here.
Long before that, I practiced linework exercises daily for a few months. These were traditional, using pencil and paper. See this post and this one for more details.