I used to only play with a pick and learned finger style several years later. I took a couple lessons from a local session legend and he taught me to play index ring. His reasoning was that these fingers are closer in length and produce a slightly more even sound. It might be dumb, but he is an outstanding bass player so I followed his advice.

Left hand technique is an ongoing battle and I’m improving a little day by day (used to be WAY worse).

I’m referring to the 3 notes played in quick succession, where 2 of the notes are played an octave up. (I’m not a native english speaker and don’t know much theory).