Believe me. It’s hard. It took me a whole day of just messing around with brushes before I could comfortably sketch in CSP. And that’s Sketching. I haven’t even really touched lineart yet.

Window>Sub Tool Detail

Though the interface may be different for you. Check out x for a sai-ish interface. I’m not going to pretend I know anything about CSP interface. All that work was done for me.

If you got that, just play around with settings. Since its the marker tool you might want to play around with pressure settings on the brush.

I couldn’t figure out how to change pressure settings for a long time but once I did it let me experiment more. In Brush sizes there should be this arrow that you click to change how your brush increases. You can change how small it goes and how big it goes.

What I didn’t know was this option is in a lot of places. They are just disabled. If you find these boxes next to a setting, you can control the pressure of various aspects.

enabling this and disabling the pen pressure settings on the brush size (kind of) makes a default marker tool. But you really have to play around to get exactly what you want