(note: I use a tablet and have pen pressure. also I use the older version of chickenpaint (chibipaint) so that's why the UI looks a bit different)
brush 1:

kinda my usual brush these days, I use it for like everything. idk what to really say about it, it's an extremely basic brush that gets the job done lol
brush 2:

one of my main lineart brushes. 2px and with pen pressure turned off. sometimes I use max opacity/color for a more bolder style, but a lot of times I just keep it halved out of personal preference.
brush 3:

idk how to describe this one. the first brush but with ~texture~ to it. I like using this one for a gritty or traditional sort of vibe
brush 4:

the classic oekaki pencil-y looking brush
brush 5:

I don't really use this for lining, so I didn't draw anything here. the square pixelated brush gives a really weird sort of messy inky effect? idk why it does so but I dig the look of it and like using it for shading. I like to use the first brush for lining then this one for shading, as seen here.
there's more brushes I could share but I'll leave it at these for now. maybe next time I'll share what I use for BG painting lol
also if anyone has any questions about how I do things, feel free to ask!