Ok so i use clip studio paint! i use most of the default brushes there, and im downloading some. let me link stuff.

For Sketching i use the a copy of the G-pen.

for messy lineart i use from the India Ink-Dry Ink brush.
and i messy color down with the Marker - Flat Marker

for more serious lineart i use the G-pen. but recently from Loish newsletter brush pack i like the loish-oil-pastel for a crunchy lineart

for coloring i use a mix of the Thick Paint group: Gouache, the Round mixing brush, and the oil paint.

And AND i found this amazing set of grass and building and clouds brushes from DevinElleKurtz:
https://linktr.ee/DevinElleKurtz

and this artist makes a lot of cool stuff and assets you can download:
from them i use the halftones and semitones
https://x.com/eriartdotnet/status/1806121556608721254

and from loish:
https://loish.net/free-resources/

let me know if i can share more stuff !