Last year my needle driver started feeling like it was burning grooves into my fingers. I agree with maxhart that stretches are a good start, but they only do so much if you're still holding things the same tight way for hours. The real fix for me was retraining how I hold my tools, like keeping my thumb relaxed instead of locked. It feels awkward at first, but it stops the problem before it turns into real damage. We spend so much time worrying about the form, but our hands are the most important tools in the room.