I like to think it comes from more actual coaching of serving than I ever saw at the club level, but based on what we saw this year at Texas, I'm not optimistic. I was consistently blown away (at the club level) by how little effort was put into coaching such a massive component of volleyball success. During warmups for practice, they'd serve for x number of minutes, and I rarely saw a coach give any meaningful form tips or impart any knowledge about how or why we serve this way or that way etc. It all boiled down to a few minutes of relatively unsupervised serving at each practice, and then at tourneys, coach telling everyone "We gotta serve tougher". OK, that's cool Corch. Now how about you actually teach them how to do that effectively and give them some more specific instruction and direction than "serve tougher, but keep it in".
Watching our serving this year, it just seemed utterly static & predictable. Nothing seemed to change within a set, from set to set, or from match to match. Each server always seemed to serve their same serve over and over, too. Maybe I'm expecting too much, but imho our serving game is in desperate need of more variation. I thought it was quite telling in the Wisconsin match when Sheffield was interiewed mid-match and, oozing confidence, said something along the lines of "We got this. We've seen every serve they have, and we can pass 'em all". That's, uh, not good. And we just continued doing the same shit over and over with the same results. IIRC the only one who seemed to be able to put any consistent pressure on them was Nya, who kept putting it deep in the corner with some pace.