I'm am no great wizard of the bass. I take lessons and practice a good bit. I find however that some of my biggest gains in playing come when I'm just fumbling around noodling. For instance... I'll hear a turnaround or walkup in my head. I'll pick up the bass, pick a key and screw around with the different walks and turnarounds that I do know and move stuff around until I figure out the exact run that I was shooting for. It's not very scientific, but as I say, it's proven effective for me. Does anyone else seem to have their bigger "aha" moments when noodling?