Three years into daily digital painting practice, here's what I know about brush settings that I didn't know at the beginning.

Opacity and flow are not the same thing. Opacity controls the maximum density a stroke can achieve in one pass. Flow controls how quickly opacity builds up within a stroke. For oil-style painting, lower flow with high pressure sensitivity gives you strokes that build up like paint. For graphic design work, higher opacity with consistent flow gives you clean fills.

The pressure sensitivity curve matters more than most beginners realize. Too light at the beginning and you lose sensitivity for feather strokes. Too heavy and the pen feels resistless. I spend fifteen minutes with the calibration tool on every new installation.

Stabilizers (called smoothing in most apps) are not one thing. There's length-based stabilization, velocity-based stabilization, and weighted averaging. Krita has the most granular control. Clip Studio Paint has the most practical balance between configurability and simplicity. Procreate's StreamLine is simple and effective but less configurable than the others.

The highest-value brush setting change I made: turning off opacity on my base sketch brush and using flow only. It forced a lighter initial touch and stopped my sketches from looking too finished too early.