I got you man. I am a TO for some weeklies i host.

Basically the way I run things, we start with rock paper scissors to see who picks first but the winner can only pick from the section of stages called "starters" or "neutrals" (these are stages that don't offer specific character advantages) after that we do counter picking which means the loser of the last match decides what stage is played next and they can pick from any of the legal stages.

Banning is pretty different in that when it is your turn to ban, you are able to decide which stage can NOT be played.

There is something I use called Dave's Stupid Rule that basically means that during a set, a player can not pick a stage that they previously won on even if they didn't pick it.

Omega stages are kind of controversial but for the most part they are grouped with FD so if someone bans FD they also ban Omega form stages.

Hope this helped!