If you want to increase the sensitivity of your fingers, heres a little excersize I learned from some crazy old guys journal (He was a picker from the forties, Keep your eyes open for it, not very new information but it's a fun read!)
Anywho, he suggests that you take some hand cream, rub it really well into your finges, and drag them slowly over a piece of sand paper, trying to feel every individual grain of sand. He also suggested using an old file cause sandpaper shwas expensive or hard to come by or something. After two or three weeks of doing this, your fingers will be much more sensitive and feedback will be a heckuvalot better.
Of course you could just practice for three weeks instead
