Just for total clarity, I assume you are talking about your right (plucking) hand?
As to the question, I really don't know the answer. 'Technique' is a sum of so many elements that singling any one out as more important than others is impossible. Every element of technique offers more oppportunities to get wrong than it does to get right. Things like left hand thumb position; fingering choices (3 vs. 4 fingers); RH thumb (floating vs. anchored); fingers vs. pick; pads vs. tips; strict alternate plucking vs. raking or 'Economy Picking'; strap length; neck angle, and so on will always spark discussion, debate and argument. But I think there are two elements that transcend all of these things, and apply equally no matter what other choices have been made, namely:
- Left/Right synchronisation. IME this is the key to speed and fluency no matter what the chosen left or right hand technique. Poor synchronisation causes undesirable artifacts at the start and end of notes such as double attacks (stop before pluck or pick), thuds (stop after pluck/pick) or even total silence. These bits of lost time tend to be highly personal and unique within an individual's technique. Left untended they also tend to be fairly consistent so they become more signficant as tempo increases and note values get shorter. For example, 20ms sync error acounts for 2% of a whole note at 60BPM, but accounts for 64% of a 1/16th at 120BPM - more silence than sound, and hardly legato! Get it down to 5ms and you now have 84% note and only 16% 'flub'.
- Use of dynamics, articulations and timbre to 'shape' lines and bring expression to the music. Poor taste in dynamics can ruin a performance, even if all the right 'notes' are placed in the right order at the right time. I use the word notes carefully, since a note is defined as much (if not more) by it's dynamics, articulation and timbre as by it's pitch. In this regard, misused compressors are the enemy of good technique because most of what you hear is not representative of what was played.