A man paints with his brains and not with his hands.

Skill lives in the seeing, not in the hand. Anyone can be taught to hold a tool steadily; what separates good work from merely competent work is the judgment that decides where the line goes and why. When your work feels flat, the problem is usually upstream of your technique.

Before your next practice session, spend part of it not practising. Look hard at work you admire and try to name the decision behind it rather than the execution. Then make one deliberate choice in your own piece and see whether the hand follows.