As a setup to this question, I should tell you that I am an old guitar player that mostly played by the three-finger picking method. This involved the index finger, middle finger and thumb. I am trying to learn how to pick the bass (at the young age of 63) and I am having to unlearn a few things from my guitar playing days. One of my biggest problem is the two-finger plucking. It's very logical in my head to rest the thumb on the pickup while I am plucking the E string, but I want to stay on the pickup when I pluck the A string also. When I drop down to the D and G strings I feel most comfortable resting my thumb on the E string. I have watched many videos of other bass players, and some are dropping the thumb down to the A string and D string, and some others do not drop as much. I want to learn this correctly, and I'm not sure how I ought to be practicing this technique. Any pointers?