I'm in a rutt. 3 months ago, I was able to play the beginning (like the first minute) of Donna Lee, and I could do it pretty damn good. Now, I'm having trouble getting past the opening line. My left hand especially is getting slower and sloppier. I've noticed this with a lot of my playing lately, not just that song. I think the problem is that I never do any warmup excercises or anything. When I pick up my bass, I usually just play. I'm not in a band or anything so I don't have anything specific to practice, so I just screw around and make stuff up. But now it's starting to catch up with me. I'm starting to tackle harder songs now, but I've been slacking lately and I'm not as good as I was. I need some good excercises to get my hands primed before practicing. Something, anything, whatever will fix this.