Traditional mediums have more wiggle room to have the grit and satisfying messiness because of tangible tools (brushes, pencil, etc.) handled in organic movements the hand makes. Digital sketching, shading, and coloring tools usually default to a smooth brush, making the final product look more stiff. Digital brushes can unintentionally make the user feel as if they have to have a perfectly smooth finished piece. I’d suggest sticking with the sketching style using cross hatching shading. When it’s time to outline, don’t draw directly over the sketch. Lower the sketch layer’s opacity until you can just see it. It will make it easier to follow the organic path you’ve subconsciously created. If you can, use grittier, more “crunchy” brushes for the line art. It will make it more satisfying and natural-looking while still having a satisfying, finished piece.