For the time being I do my digital sketching with a generic hard edge circle brush, but kind of thick so a lot of my sketches look kind of blobby lol. Which is in stark comparison to traditional, where I prefer to sketch with mechanical pencil or especially ball point pen which leave very thin lines obviously. I'm still new-ish to digital art though and so not completely sure if I'd prefer emulating my traditional sketching more closely, or just leave them each as their own thing ¯\_(ツ)_/¯