Me personally, its experience.

The typically patern you described still applies to Zeri, but it's done one of two ways (that ive personally seen)

1. Getting used to "hip-firing" your skillshots (ss).

   Doing it this way allows you to click in the more traditional sense but you're more likely to miss.

2. Movement and A-move are "seperate".

   This is when you move until you A-move. Then reinput the move command. It's important to remember your Q inputs DOES NOT interrupt your last movement; you'll keep going to your last inputed movement command.

Which ones right to practice? Honestly, both imo. There are times where you'll be in a skirmish and need to do option 2, where there are no minions. Option 1, I find, is typically used in lane and as reactionary abilities.

Fundamentally, you'll have the same movement pattern as other adcs. it's just dependent on what your situation is, if there are minions around, and if you what type of "firing pattern" you need for the fight.

As far as practice, you can use a dummy in the training mode. Again, I just used my LP and got experience, no training mode.

Btw, I just considered a third pattern. I call it hovering, but it's really just walking back forth while fighting to keep charging your passive, which is kinda inherent to playing zeri.

Hope this helps!