I was asked by a few, and I definitely promised one person that I'd give them the settings for the two brushes I use the most. One for sketching and one for inking.

Inking- It's a copy of the "Ink Pen" tool. Not the normal pen tool (I don't know if this changes anything). Along with these settings, I usually change the stabalizer that's in the top bar of SAI to fit my preference every day. This simply changes how bold some of my strokes come out.

Sketching- Well, anyone can sketch with anything. This is just the settings I really enjoy because they make the lines wispy looking and have an opacity to them I find appealing. I only used this brush when sketching this: https://www.furaffinity.net/view/10573145/

And that's what I use the most. Coloring is different all the time, and I just use default ink pen and/or airbrushing for that. Usually my airbrush has fuzzystatic set instead of (Simple circle).