I usually start a phrase with the index finger, but not always. When I go down from the G string to the D string or even over more strings, I rake mostly, i.e. use the same finger for all notes. That's how I have always done, I'm mostly self-taught, I've had only four lessons and I had them after having been playing for about 3-4 years...
The bad thing with raking is that the latter notes easily get out of time. I've tried to learn strictly alternating fingering technique but I just can't get that working. So for me it's better to work on the timing issue I guess, It's just the matter of raking with the right speed. James Jamerson could do it so at least it is possible....
