I've been asked what program I used to work and what kind of brushes do I use.
Well, here they are! They are for Clip Studio Paint and these are the ones I use to make linearts and sketches, for colors I use the solid G-Pen, so yeah.
The lines I use are made on the Subtool Brush (B) > Watercolor. Go nuts!
Some of them are pretty basic but maybe they can help you in one way or another.
Spread the word! THEY ARE FREE!!!!!!!!