Personally I've been watching Choco play as the way he plays her really fits my style. He focuses on spacing in neutral with Plasma Whip, Z-Air, F-Air, B-Air, and N-Air, using Jabs when close, mixing it up with some Smash Attacks. He uses ZSS' good aerial mobility and Down B to move around his opponent for good spacing. He uses Smash Attacks, some Edge Guarding, and Up B to kill. He'll sometimes throw out Neutral B to mix it up a bit but doesn't use it very often.
It's very different from how she was being played in Smash 4 with a lot less of a focus on combos. I think this has to do with a lot of combo potential being nerfed but her Neutral spacing tools being buffed. All her aerials have less landing lag besides Z-Air, B-Air has two hitboxes now with a sour spot hitbox on her thigh, Z-Air now does consistent damage and has less aerial end-lag, all her throws have less end-lag, sweet spot Plasma Whip does more damage and significantly more knockback, and Flip Jump also moves slightly faster. She also good some huge movement buffs with her initial dash going from 1.7 to 2.42, her run speed going from 2.1 to 2.31, and a slightly buff to aerial speed going from 1.2 to 1.26 which all help her maneuver around her opponent easier.
Here's two videos of Choco playing in a tournament. He's won one tournament with ZSS and came second in another which is this one.
https://youtu.be/YncML8yi7Zw
https://youtu.be/kkBbUv-drRA